Omaha, Nebraska

THE PULLMAN PROJECT An Investigation into the Development of a Green Building in Omaha, Nebraska

THE OMAHA GREEN BUILDING COUNCIL Nebraska State Recycling Association Joslyn Castle Institute for Sustainable Communities and Inner-City Coalition on the Environment

May, 1999

Funding for this project was provided by the United States Environmental Protection Agency (US EPA) and its Sustainable Development Challenge Grant program.

THE OMAHA GREEN BUILDING INITIATIVE

Funding for this project was provided by the United States Environmental Protection Agency (US EPA) and its Sustainable Development Challenge Grant program. We extend special thanks to Richard Sumpter, EPA, Region 7 staff person in Kansas City.

DEDICATION

This report documents a herculean eflort by a large and diverse number of Nebraska individuals and groups who share a love for the environment and apassionfor conservation in all its forms. No one person better exemplij?es this spirit of community cooperation and creative problem solving than Bob Light, former owner of the Pullman Hotel. As the research for this project evolved, the hotel began to be called “Bob’sBuilding” by everyone. He generously hosted tours and inspections, and gave total access to all of our project volunteers -- no strings attached.

Bob Is dream was a like-new “green” building that would be his personal residence, but illness forced him to sell the building. The Nebraska State Recycling Association (NSRA) dedicates this document to the spirit of

“Bob’s Building ” and renewing our commitment to “green-ness,’? wherever we manage to find it.

To Bob. Good Health and God Bless. THE OMAHA GREEN BUILDING INITIATIVE

The Green BuildingEco Park Project was a community-based effort that could not have - taken place without a tremendous number of volunteer hours contributed by numerous individuals, groups, and businesses. The “Green Building Council” was organized to include a Management Team, five working committees, and a number of paid and volunteer consultants. To all of these partners, we extend our appreciation. Their participation has enhanced our efforts and hopes for a “greener” future for Omaha.

We are grateful to the following for their contributions of time, ideas, hard work, and support.

Management Team Site Selection Committee Steve Andrews Kay Stevens Jim Ault Executive Director, Francis Boggus Nebraska State Recycling Association Janet Bonet John Dineen Catherine McGuire, AIA Bruce Ehrich Executive Director, Angela Eikenbeny Joslyn Castle Institute for Carrie Hakenkamp Sustainable Communities Gene Hanlon Barbi Hayes Elizabeth Stevens Julie Kalkowski Associate Director, Deron Lawrence Joslyn Castle Institute for Patrick My Sustainable Communities Bob Light Catherine McGuire Barbi Hayes Dan Montez Inner-City Coalition Rudy Novacek on the Environment Pat Slaven Jim Steffan Elizabeth Stevens Kay Stevens Paul Thomsen

Remediation Committee Janet Bonet Bruce Ehrich Carrie Hakenkamp Barbi Hayes Deron Lawrence THE OMAHA GREEN BUILDING INITIATIVE

Building Design Committee Landscape Committee Finance Committee Ron Baker Rachel Bender Kim Bonniwell Francis Boggus George Bryan Eric Bunderson James Dahlin Jeff Fahs Christian Christensen John Dineen Cynthia Fitzgerald Jeanne Eibes Dan Donahoe Mike Gulbrandsen Gene Hanlon Angela Eikenberry Sara McCandless Sheme Hanneman Karen Falconer-A1 Hindi Maureen Monohan Julie Kalkowski Tony Hazuka Glenn Pollock Pat Langan Kama Helmstadter Pat Slaven John Luce Dan Kammerer Elizabeth Stevens Michael Maroney Kerry Keelan Trilety Wade Mary Potmesil Partrick Leahy Dennis Smith Larry Liss Jim Steffan John Luce Kay Stevens Bruce Maine Rob Stevens Waddell McGee Catherine McGuire Eric Nation Lou Paladin0 Dorothy Patach Joyce Slezak Cathy Wagner Michaella Wright Professional Consulting Services were provided by: Greg Franta, FAIA, ENSAR Group, Inc., Environmentally Sustainable Architecture Fiona Cousins, PE, Ove Arup and Partners, Mechanical Engineering Martin H. Shukert, AICP, RDG Crose Gardner Shukert Murray Milne, Professor, University of California, Los Angeles (Energy Design Tools)

The Design Committee benefitted from the special assistance of the following: Dan Donahoe, Mechanical Engineer, Leo A. Daly Company Michael A. Naccarato, Structural Engineer, Leo A. Daly Company Mike Kuhse, Structural Engineer, HDR Architecture James Dahlin, 3D Architectural Drawings, DLR Group Omaha Public Power District for guidance on ground source heat pumps Nebraska Public Power District for guidance with photovoltaic applications

John Luce and Pat Dill of John Luce Company contributed over 200 hours of time developing construction cost estimates through the program development and preliminary design process.

The Student Design Competition was co-sponsored by the University of Nebraska College of Architecture,

Yankee Hill Brick of Lincoln, and the Federal Home Loan Bank of Topeka. ~~

Mike Gengler of Joslyn Castle Institute for Sustainable Communities illustrated green building concepts for this report.

Tim Wentz, President of the Nebraska Chapter of ASHRAE and Professor at UNL and students in Mechani- cal Systems investgated construction management issues.

A special thanks to HDR and OPPD for their donations of funds and space to host two Green Building Council meetings. .. . 3 THE OMAHA GREEN BUILDING INITIATIVE

Introduction 1

Chapter One Project Background and Objectives 3

Chapter Two The Site Selection Process 6

Chapter Three The Building Design Process 10

Chapter Four Systems and Material Selection 22

Chapter Five Eco Park: The Pullman Building in the Urban Landscape 38

Chapter Six Project Cost Estimates 46

Chapter Seven Project Feasibility and Financing 49

Chapter Eight Applying Green Building Principles to Other Projects 53

Appendix Sustainability Report: The Pullman, Omaha, Nebraska Ensar Group, Inc.

Green Building/Eco Park, Omaha: Building Mechanical Design Report Ove Amp & Partners

THE OMAHA GREEN BUILDING INITIATIVE

INTRODUCTION

OMAHANS, in common with other Americans, express increasing concern about such critical environmental issues as global warming, excessive energy consumption, and the inefficiencies of a disorganized and decentralized development pattern often referred to as “urban sprawl.” Yet, we rarely translate these concerns into actions. Omaha continues to develop in a manner that spreads urban development across the countryside at low densities. Between 1950 and 1999, the population within the city limits has grown from about 250,000 to 350,000, an increase of about 40%. However, the city’s area has almost tripled during this same period, growing from 40 to 110 square miles. This revealing comparison does not include suburban and rural development in Douglas County and surrounding metropolitan counties. Our preferred lifestyle uses more space, and consequently requires more resources and energy to sustain itself. Ulti- mately, we reach a point where we can neither support our energy consumption habits, nor do very much to change them.

In 1992, the United Nations Conference on Environment and Development, often referred to as the “Earth Summit,” convened in Rio de Janeiro. The conference posited the concept of sustainable development as a solution to the paradox of encouraging international development while addressing growing long-range environmental concerns. Sustainable development can be defined as development which uses resources to create an acceptable standard of living

Page 1 - THE OMAHA GREEN BUILDING INITIATIVE

In order to investigate the concept of local sustainable development, three organizations with a shared concern for the urban environment applied for and received a planning grant from the Environmental Protection Agency to plan a Green Building development in Omaha. The participating organizations included the Nebraska State Recycling Association (NSRA), the Joslyn Castle Institute for Sustainable Communi ties (JCI), and the Inner-City Coalition on the Environment (ICE). The goals of the project were to:

Establish a broad-based community consortium of organizations and professional volunteers, a “Green Building Council,” to investigate and promote the development of a Green Building and Eco Park project in particular and sustainable development patterns in general. Identify a specific project to demonstrate the application of Green Building and Eco Park practices and technologies. Add to the state-of-the-art of building, rehabilitation, site development, and landscape practice in the Omaha community and identify methods that can be replicated in other local projects.

This technical report summarizes the results of the experience that began with the award of the Sustainable Development Challenge Grant by the EPA in July 1997. After an intensive review of candidate projects, the Green Building Council focused on the adaptive reuse of the former Pullman Hotel, a 25,000 square foot, four-story structure at 1W and Pacific Streets, on the southern edge of Omaha’s Old Market district. This document provides a case study of planning for the rehabilitation of this structure according to Green Building principles. Its lessons apply to other projects in Omaha’s active program of adaptive reuse of historic downtown buildings. This document is organized into the following sections:

Chapter One considers the project’s background and basic assumptions that guided the planning process. Chapter Two reviews the site selection process, leading to the selection of the Pullman Hotel as the proposed project. Chapter Three considers the building design process and identifies basic design principles. Chapter Four considers specific building components and options, including mechanical systems, daylighting systems, and building materials. Chapter Five considers site landscaping and integration of the building into its larger urban environment. Chapter Six presents cost estimates and trade-offs of “green” technologies and materials. Chapter Seven analyzes financial feasibility, examines the projected financial performance of the project, and identifies financing requirements. Page 2 THE OMAHA GREEN BUILDING INITIATIVE

Chapter One PROJECT BACKGROUND AND OBJECTIVES

MOST BUILDING PROJECTS are designed to satisfy a client’s building program - designing and arranging space to accommodate functional needs efficiently and effectively. Ideally, buildings also should make a positive (and in some cases distinctive) contribution to their environment. “Green” buildings add two other primary considerations to functional and aesthetic program requirements: they place a high value on the impact of construction and operation on the natural environment; and they are heavily engaged in accommodating the comfort, health, and safety of occupants. While these additional concerns are part of the design of all buildings, they carry special significance for the design of green buildings.

Building Impact

Building construction and operation affects environment and health in its use of energy, materials and land. For example, coal combustion and nuclear fission produce most of , the Omaha metropolitan area’s electricity. Coal burning produces both air pollution and carbon dioxide, a greenhouse gas that retains reflected solar radiation, contributing to the warming of the world’s climate. The long-term effects of human-induced warming are a subject of considerable debate. However, a growing body of evidence suggests that global warming can threaten life and certain ecosystems, create major changes to the climate in certain regions of the world, and increase the incidence of natural disas- ters. In addition, air pollution caused by the burning of fossil fuels creates health problems and causes acid rain, which can severely damage forests. Electricity produced by nuclear fission generates long-lived radioactive wastes. Despite two decades of research, no satisfactory solution exits for the safe, long-term storage of these hazardous by-products of consumption. More than 40 percent of energy in the United States is consumed in buildings, most of which is used for cooling, heating and lighting. Reduc- tion of building related energy consumption clearly serves our long-term interests.

Green buildings use less energy from non-renewable resources because they take advantage of local climates, using solar energy for heating or cool outside air for cooling and natural daylighting for ambient light. As much as 50 percent of energy can be saved reducing operating costs and minimizing pollution. These savings reduce the initial cost of mechanical systems by lowering capacity requirements and cut ongoing operating expenses. An energy efficient building reduces environmental impact and

conserves consumable resources, thereby meeting the standard of “sustainability” by preserving resources for future generations.

Page 3 THE OMAHA GREEN BUILDING INITIATIVE

Building Materials

Building materials also effect the environment and health of building occupants and users. The mining of materials disturbs habitats and causes erosion and water pollution. The harvesting of forests for lumber can also result in loss of habitat and allows further increase of CO, levels. In addition, materials can emit toxic substances during both manufacturing processes and routine building occupancy. Poor indoor air quality in buildings can cause illness and fatigue. In “green buildings” materials are selected to minimize these negative effects.

Green building techniques also improve the productivity of building occupants. Studies show that worker performance improves in working environments with natural daylighting and high indoor air quality. Research by the Rocky Mountain Institute indicates that workers have fewer sick days and overall productivity can increase from 6 to15%.

In addition, the reuse of existing materials and buildings where possible are a principle of sustainable design practice. Recycled materials can reduce the demands for raw materials and reduce the quantity of construction waste that goes into landfill. Reuse of existing buildings saves energy and reduces the waste stream into area landfills. A study by the Metropolitan Area Planning Agency (MAPA) indicates that as much as 22 percent of landfill material in the metropolitan region is attributable to building demolition and construction waste.

Land Use Patterns and Sustainable Development

In Omaha and across the nation, citizens are increasingly concerned about “urban sprawl,’’ the unstructured spread of low-density urban development across the rural and agricultural landscape. Sprawl increases the cost of infrastructure and public services, increases the use of energy for transportation, and takes rich land out of agricultural use. The concept of sustainable development by no means calls for a halt to new urban growth; it does call for a reordering and restructuring of land use patterns to use financial and energy resources more effectively.

A fundamental technique of sustainable development is to make maximum use of ~ existing building and infrastructure resources. Therefore, the Omaha Green Building ~ Initiative focused initially on the reuse of an existing building, rather than the construction of a new facility. Another principle involves encouraging land use patterns which ___ reduce the need for vehicular transportation. Thus, development of housing near downtown employment centers reduces the need for workers to drive to their workplace. Additionally, mixed use developments with good pedestrian connections among office, residential, and shopping uses can reduce automobile trips. Page 4 THE OMAHA GREEN BUILDING INITIATIVE

Green Building Benefits

Major objectives for the application of green building principles include:

Minimizing energy use while reducing the cause of air pollution at its source,

Reducing use of toxic substances and providing a healthy environment for building occupants and residents,

Ensuring good indoor air quality and reducing health care costs,

Providing natural daylighting and ventilation, consequently increasing workplace productivity.

Reducing the initial costs and long-term operating costs of mechanical systems.

Making efficient use of resources and eliminating waste, t Using local and renewable resources, reducing transportation costs for goods and services, and

Integrating an outdoor landscape into a building project, even within a dense urban setting.

These objectives in turn determine building uses, design configuration, selection of materials, and methods of heating and cooling

These benefits have tangible and long-term economic, social, environmental and politi- cal dimensions. However, isolated green building projects will not significantly improve living conditions or protect the environment. Instead, this project is intended to demonstrate the potential of green building practices in Omaha so that others will understand their applications and economic benefits. Conventional building design produces many undesirable and unintended outcomes, including air pollution, depletion of natural resources and the introduction of toxic substances into our environment and landfill. A series of simple, cost-effective green building practices, including good design and planning, careful choice of building site and orientation, and use of construction materials and other equipment can meet the goals of functional and economic building development and conservation of our natural environment and resources.

Page 5 THE OMAHA GREEN BUILDING INITIATIVE

Chapter Two THE SITE SELECTION PROCESS

THE SITE SELECTION COMMITTEE OF THE GREEN BUILDING COUNCIL completed its work between September and December 1997 with the selection of the Pullman Hotel at 1017 South loth Street as the project site. At the beginning of the process, the Committee established reuse of an existing building and site as its primary project objectives, and identified 40 potential sites in the eastern part of Omaha as project candidates. Candidate buildings included a wide variety of structures, including vacant or underused shopping malls, former schools, an historic railroad station, unused packing houses, museums, a brewery, a car dealership, and former government buildings.

The committee established Phase I screening criteria to identify a short list of sites to be considered in more detail. These criteria included:

Site availability. Sites that were either not for sale or that required public interven- tion through the city’s redevelopment powers were discounted.

Location in the city’s designated Enterprise Zone or in another location with opportunities for significant community development benefits. An appropriate site should be visible within a neighborhood and have development benefits beyond the bound- aries of the site.

Adequate site area for Eco Park and parking development. The EoPark concept was to provide a landscaped environment to continue the principles of green design into the project’s urban environment. Adequate site area to carry out the concept, as well as to provide supporting parking for the project, is highly desirable.

Minimum space for mixed use development. Mixed use development can use space more efficiently and create a more urbane mixing of activities. In addition, comple- mentary uses can reduce total parking requirements by having peak parking requirements at different times of day. Sites that were too small to accommodate a mix of ~ uses were discounted.

Structural and remediation concerns. For economic and liability reasons, the ___ project site should avoid locations with substantial environmental remediation costs or major structural problems.

Historical value. Buildings of historic significance or contributing to the character of an historic district were favored. Page 6 THE OMAHA GREEN BUILDING INITIATIVE

Probable cost of acquisition and rehabilitation. Probable project feasibility was a key consideration for this implementation-oriented committee.

A rating of candidate sites relative to the screening criteria is included in the Appendix. The initial screening reduced the candidate list to the following sites:

1) Ames Plaza at 56&and Ames, a vacant shopping center with an interior mall, developed around 1960. The center formerly included a department store, grocery store, and other shops and offices.

2) The Livestock Exchange Building, an historic office building and the administrative center of Omaha's once dominant livestock market.

3) The former Wilson Packing Plant at 29" and W in South Omaha.

4) The Veylupek Construction building, a vacant structure at 30thand Upland Parkway in South Omaha.

5) The former Boys Club building at 20"' and Burdette in North Omaha. The Club vacated this building after its purchase of the former Flanagan High campus in 19%.

6) The former Novak Cadillac dealership, a 65,000 square foot structure at 25* Avenue and Dodge on the edge of Downtown Omaha.

7) The Independent Telephone Company at 936 North 24* in North Omaha's Kellom Heights redevelopment area.

8) The former Lake School (now a Seventh Day Adventist religious day school) at 20* and Lake Streets.

9) The former Pullman Hotel at 1017 South 1W Street.

Phase I1 Site Evaluation

The committee then developed Phase I1 criteria with which to evaluate these nine sites. The more detailed criteria included:

Community support and impact, including emotional connections to the building, its physical or geographical importance to the surrounding community, its ability to inject new life into the neighborhood, and its economic development potential.

Page 7 THE OMAHA GREEN BUILDING INITIATIVE

__- The character of the structure and site, including its visual and architectural quality, historic value, general condition, and the presence of probable environmental remediation problems.

Cost andfunding issues, including acquisition cost per square foot, probable remediation and restorationhehabilitation costs, likely operating costs, and the probability of supplemental funding through the city or other agencies.

Injj-astructure, including transportation service, pedestrian access, and the presence of other public services.

Compliance of probable building uses with zoning ordinances and the city’s comprehensive plan.

The Phase I1 evaluation reduced the candidate list to five sites, including Veylupek Construction, the Livestock Exchange Building, Ames Plaza, the Pullman Hotel, and . the Novak Cadillac building. A subsequent ranking of these five sites rated the Veylupek Building most suitable for green building conversion, followed by the Live- stock Exchange Building, Ames Plaza, the Pullman Hotel, and the Cadillac building. The Livestock Exchange Building was acquired by the City of Omaha and will be reused as part of the city’s Stockyards Redevelopment Project; as such, the building will be conveyed through the city’s redevelopment process and was not available to the Green Building Council. Ames Plaza proved unavailable and financially unfeasible (given the magnitude of the Council’s potential funding). As a result, the Veylupek Building and the Pullman Hotel emerged as the finalists for green building consideration.

Environmental Site Assessments

After the Site Selection Committee narrowed the field, the Site Remediation Committee completed a Phase I Assessment of the two final candidates.

Pullman Hotel. The Pullman’s current use at the time of a December 17, 1997 site visit

included a restaurant and bar on street level and some residential uses on upper levels. ~ A walkaround indicated no evidence of fuel storage tanks, fill covers, or groundwater wells. The building’s owner retained ATC Environmental, Inc. to complete an asbestos inspection. Three of nine samples taken tested positive. The owner then caused the - asbestos to be removed, confirmed by a subsequent inspection by ATC. The history of the building indicates continuous residential or lodging uses, unlikely to produce hazardous conditions. The site is not included on either the RCRA or CERCLA list- ings, and the LUST division reported no documentation of underground storage tanks. While detailed assessment and appropriate handling of other environmental threats, Page 8 THE OMAHA GREEN BUILDING INITIATIVE most notably lead-based paint, should be completed during construction, the Remediation Committee concluded that a Phase I1 assessment was unnecessary.

Veylupek Construction site. This site includes three buildings: a five-story structure used for industrial and grain storage purposes, a two-story building housing office and industrial uses, and a one-story garage. A cursory inspection indicated no evidence of above-ground fuel tanks or wellheads. Historically, the site has been used for a variety of purposes, including feed manufacturing, a brewery, grain storage, and a variety of small industries. Based on this history and the appearance of the site, the Committee recommended completion of a more detailed assessment of the property before pro- ceeding with planning.

The Pullman Hotel Decision

The Site Selection Committee’s work concluded with the selection of the Pullman Hotel as most consistent with the Green Building Council’s vision for the project and having the best likelihood of successful completion. Specifically:

1) The Pullman Hotel had a lower probability of environmental remediation issues than the Veylupek site.

2) The Pullman is more visible and has reuse potential that responds to demonstrated market demands in the downtown area.

3) The reuse of the Veylupek site is likely to be more expensive, with lower expectation of revenues, than a Pullman rehabilitation.

4) The Pullman Hotel is located within a district listed on the National Register of Historic Places, providing the additional benefit of tax credits for certified rehabilitation.

5) The Pullman provides opportunities to demonstrate techniques directly applicable to a significant class of market activity, specifically the adaptive reuse of buildings in and around the Old Market district for residential and commercial purposes.

Page 9 THE OMAHA GREEN BUILDING INITIATIVE

Chapter Three THE BUILDING DESIGN PROCESS

AFTER THE GREEN BUILDING COUNCIL SELECTED THE PULLMAN HOTEL AS THE SITE FOR THE GREEN BUILDING STUDY, the Buildir g Design Committee began work. The objectives of the committee were to:

1. Define a program for the Pullman Hotel that would meet market demands and would provide a reasonable expectation of return on investment.

2. Develop a design for the building that would illustrate the application of Green Building concepts in Omaha.

Building Assessment

The first step in the design process was an assessment and code review of the existing Pullman Hotel building. This assessment helped to determine the scope of the building project and evaluated the potential for reusing existing systems and materials in the structure.

General Building Assessment: The Pullman Hotel is a four-story building above a basement, with a footprint of approximately 5,200 square feet. The building provides approximately 25,000 square feet of gross floor area, including its basement level. The basement is open to the north and east. The Pullman is a post-and-beam structure, with some first floor beams requiring replacement. Portions of the basement ceiling are deflecting, causing water to leak into the basement. Wood posts have experienced fire damage on one level. The roof appears to be in good condition.

Mechanical and Electrical Systems: Electrical systems are generally obsolete and require full replacement as part of an adaptive reuse project to contemporary standards. The building is steam heated, using radiators in rooms. This system also requires full replacement. Plumbing fixtures also will require full replacement.

~ Architectural Considerations:The Pullman is configured in its original plan as a

“railroad hotel.” This configuration may lend itself to single room occupancy, but is - not adaptable to current expectations in the Old Market residential market. Walls are wood stud construction with plaster and lath.

The building’s entry hall retains some historic finishes. However, its formal stair, once open, has been enclosed to meet fire codes, obscuring an historic balustrade. A Page 10 THE OMAHA GREEN BUILDING INITIATIVE fire escape provides alternative egress.

The current elevator is inoperable, but the shaft is intact. The elevator does not provide service to the roof.

Code and Life Safety Issues. The existing enclosed stair does not provide a two-hour fire rating. Distance between exit stairs is also inadequate to meet code requirements. A new rated stair enclosure may allow the historic stair to be opened and restored. A change in building use will require maintenance of two fire-rated stairways and provision of sprinklers. The three upper levels will not require sprinklers if maintained in residential use. All construction should follow NPFA 101- 1994.

This general review led the Design Committee to the conclusion that the Pullman project should be envisioned as a “gut” rehabilitation. The scope of a project includes interior demolition down to the supporting structure, replanning of the building and replacement of walls and all interior finishes and building systems.

Building Program

The Pullman Hotel, at lo&and Pacific, is located on the edge of a district undergoing substantial land use and investment changes. The building is located in the city’s Rail and Commerce Historic District, listed on the National Register of Historic Places. Its site is a transitional property between the railroad and Old Market districts and the Near South residential area. The Pullman Hotel is adjacent to the historic but vacant Burlington Station, originally designed by the great Omaha architect Thomas R. Kimball and modified in 193 1 by Graham, Anderson, Probst, and White. Immediately to the north, on the opposite approach to the 1W Street Viaduct, is Gilbert Stanley Underwood’s Union Passenger Depot, now the Durham Westem Heritage Museum. The lcyb and Pacific intersection is marked by neighborhood restaurants, transitioning to the residential avenue of loa Street to the south.

Major market and physical forces affecting choice of a building program for the Pull- man include:

I. 7he continuing success of residential adaptive reuse in the Old Market and Rail and Commerce Historic Districts. After the initiation of residential reuse programs in the early 198Os, these downtown districts have experienced development of over 2,000 housing units. The pending reuse of the Buttemut and Ford Warehouse Buildings, both of which border the 10ulStreet Viaduct just north of the Western Heritage Museum, put the Pullman in a position to benefit from this continuing trend.

Page 11 THE OMAHA GREEN BUILDING INITIATIVE

2. The success of the nearby Town view Terrace and Pierce Pointprojects. These single-family urban developments established strong residential markets in the transition zone between downtown and railroad districts and the adjacent Near South neighborhood.

3. The lothStreet viaduct reconstruction. This viaduct, carrying lW Street over Union Pacific and Burlington Northern & Santa Fe mainlines, a Union Pacific multi-modal facility, and land once occupied by the extensive station trackage of the Omaha's two principal railroad stations, will be reconstructed in the near future. The new design is historically sympathetic to the surrounding environment and the character of the existing bridge and will include provision for a future heritage streetcar line along 1W Street. This will further strengthen the link between the Pullman site and the Old Market district.

4. The l0"h Street Streetcar. This City of Omaha proposal will link Downtown Omaha to the Henry Doorly Zoo and Rosenblatt Stadium via the IO* Street Corridor. This transit link would strengthen the connection between the Pullman Hotel and 1W and Pacific intersections with the Old Market, Downtown Omaha, and other important features along a growing tourism corridor. The streetcar project is currently on hold, but remains a significant long-term city objective.

This review of market trends led the Building Design Committee to recommend a mixed use building concept, combining office and commercial uses at street level with residential uses on upper levels. The detailed program includes the following elements:

Street Level: Street level uses will include office space on the north side of the building and commercial space, potentially a caf6 or coffeehouse, on the l@and Pacific exposure to the south. Both spaces would have access from 1W Street. For a cafe use, outdoor seating may be developed on the south side of the building.

Upper Floors: Residential and office uses were considered for the Pd,3"', and 41h building floors. The market for residential development appears more substantial than that for office development at the 1P and Pacific location. The recommended residential floor plan produces seven studio units per floor, with sleeping alcoves located off principal living spaces. An altemate concept, discussed below, produces four units per floor and features intemal ventilation stacks.

Original planning studies included reuse of the upper floor as a large condominium for the owner of the building. Under this scenario, the project would include rough-outs of plumbing and mechanical systems to the upper floor, with finish construction completed by the owner. However, the analysis contained in this document anticipates the conversion of all three floors into apartment units. Page 12 THE OMAHA GREEN BUILDING INITIATIVE

Lower LeveZ: A steep west to east fall in grade provides the Pullman Hotel building with a walkout basement level on the east. Original programming anticipated development of a community meeting hall and other public facilities on this level. However, a successful project must provide residential support features consistent with those offered by compet- ing buildings in the downtown market. Thus, the building program for the lower level includes provision of limited indoor parking and apartment or condominium storage facilities.

Vertical circulation and support spaces: Circulation should be minimized because of the relatively small footprint of each floor. A single pair of restrooms is programmed for street level, to be shared by building occupants. An altemate plan provides two pairs of smaller restrooms, each serving one of the street level leased spaces.

Roc$ The project proposes developing a roof garden for use by building residents, incorporating a viewing deck, planters, landscaping, and an array of photovoltaic cells. The roof should be accessible by elevator and at least one stair. Stair placement and appearance should not compromise the historic character of the building facade.

9 Public spaces: Public spaces and lobbies in the building should accommodate displays illustrating green building concepts. Public access to the roof was also considered.

Building Design Solution

The plan drawings included in this document present the reuse concept for the structure. The plan includes the following features:

Building core: A central circulation core is defined in the building, consisting of an elevator and two stairways. The west stair encloses an existing open stairway and provides access out to 1P Street. An east stair would be built by filling an indentation in the eastern facade of the structure. A new elevator shaft will be constructed adjacent to the existing shaft.

Lower level: The plan provides garage parking for up to six cars. Parking access is provided from the walkout exposure to the east. Covered parking in the Downtown Omaha market typically yields between $50 and $70 monthly. The balance of the lower level is used for private storage and mechanical equipment.

Street level: The street level solution produces a 2,330 square foot office space on the north side of the building and a 945 square foot commercial storefront on the south. Each space should include storefront windows sheltered by awnings, as well as entrances from 1W Street, the building’s primary commercial exposure. A secured apartment entrance is provided in the middle of the building, leading to stairs and the elevator lobby. Street Page 13 ~~ ~ THE OMAHA GREEN BUILDING INITIATIVE

level bathrooms are provided either within the secured area, for use by first floor ~ occupants and customers, or within individual leased spaces.

Upper levels: Each upper floor provides seven studio apartment units, ranging in size ~ from 517 to 730 square feet. Each unit includes a living area, kitchen and dining area, sleeping alcove and bathroom. Plumbing is stacked for maximum efficiency. A central circulation area links the elevator and stairways and provides access to each unit.

An alternate design concept provides four larger residential units per floor, each served by a vertical ventilation stack. The stack demonstrates green building techniques by reducing the necessity for mechanical ventilation. The four-unit alternative also provides the flexibility to convert to office uses. However, the seven-unit alternative was selected as the preferred option because of its ability to fulfill a demand for smaller units and to maximize revenue per square foot. In addition, given the strength of the downtown residential market, a future conversion from residential to office use in a building with a small footprint is relatively unlikely.

Roof deck: A roof garden and deck is proposed for the northern part of the roof area with ground cover and a photovoltaic array on the south part. One stairway and the

It I t r I I L I I I t-1 c-: I I I- 4-c

I I I I TMWfDRooRPu)( 6

~~ An alternative design for the Pullman provides individual bathroomsfor each street level leased space. These plans also illustrate the potential location of ventilation stacks. While these are not included in the concept analyzed in this report, stacks are an especially useful concept in large footprint buildings, such as the conversion of warehouse structures into apartments. Page 14 THE OMAHA GREEN BUILDING INITIATIVE elevator are extended to the roof and connected by a vestibule.

Building Elevations. Building elevations will be consistent with the Secretary of the Interior's Standards for Historic Preservation. The predominately residential building program will require new penetrations on the building's south exposure. New windows would follow the rhythm and form of existing windows in the building. Following the pattern established at the Greenhouse adaptive reuse project in the Gene Leahy Mall, sash color may be used to differentiate between historic and new windows.

Storefronts at street level will be replaced with new fenestration and entries. Canopy or awnings should be used along the 1o"h and Pacific Street exposures.

Green Building Design Issues

The previous discussion outlines functional building program decisions and design solutions. This section considers the design process related to green building and environmental performance considerations. Systems that relate to mechanical performance, daylighting, and material selection - the key components of the Green Building design - are considered in further detail in the next section.

After defining the building program, the committee identified and studied major components of green design, including energy design, indoor air quality, energy efficient systems and equipment, daylighting and lighting, renewable energy, materials and products, recycling, water conservation and water quality. A focus of the committee's work was integrating green building concepts into the overall design program.

While members of the Building Design Committee could address many aspects of green design, others required specialized consultation. The committee retained a consulting architect and mechanical engineer to integrate design and engineering solutions for the green building. This consultant group included:

Greg Franta, FAIA, a principal architect of ENSAR Group, an architectural firm based in Boulder, Colorado specializing in environmentally sustainable architecture; and

Fiona Cousins, P.E., Associate of Ove Amp & Partners, a mechanical engineer with considerable knowledge in the thermal analysis of buildings and in natural ventilation.

The findings and recommendations of these consultants are incorporated into this narrative. Their full reports are included as an appendix to this document. Other important systems, notably lighting design, were not addressed in detail at this conceptual Page 15 \ @) \

CONDO STORAGE

f -E --

CONDO CONDO STORAGE STORAGE

CONDO ;TOR AGE

WECHANICAL ROOM

SCALE: ,,e' = ,' ______-______0"

rr.(rc 71th Eco-Park Architecture D.8. mx PRELIMINARY PIAN 10-13-98 I

+-- ._ -+I+---.- OFFICE 1 NSRA

I 1 I I i i i i

STUDIO CONOO

STUDIO CONDO

SCALE: ,/a" P l'______-_-_____----- 0"

?.*d Tltl. Eco-Park Architecture D.1. mx PRELIMINARY PLAN 10-13-98 N FOURTH FLOOR PLAN SCALE: i/a' .I,------0'

Prrq-1 1111.

Eco-Pa rk D.,. mT Architecture PRELIMINARY PIAN 10-13.91 .' I I i

n...... “ ....~ .._..-, I 572 SO. FT. 1 ;11111 I I1 (:IINIIII

I . ?..(ai 1111. Eco-Park 0.1. PRELIMINARY PLAN 9-22-98 m ma m m a m m m L

III W. +3. 3 W

’I ’I I m m m m m m m m m 1 m m

m m I II]

THE OMAHA GREEN BUILDING INITIATIVE

Stair Ventilation Stacks \ /

/ \ New Exterior Mechanical Stair

View from the Southeast

Page 16

THE OMAHA GREEN BUILDING INITIATIVE

Residential Floors

\ Operable Windows with High Performance Glass

View from the Southwest

Page 17

THE OMAHA GREEN BUILDING INITIATIVE stage.

Design Process

The Building Design Committee considered the primary aspects of the design process to include:

1. Assessment and design tools. 2. Green building concepts . 3. Climate and existing building design.

The committee considered a number of green building concepts to improve building performance and create a healthier environment. The challenge was to understand the relationships among the concepts and to identify those features that would be most effective in the Omaha climate.

mmt an$ Deslgpt Took

Assessment tools establish levels of achievement in green building design. The committee employed the U.S. Green Building Council’s LEED system, a new national certification program for commercial buildings developed by representatives of government agencies, the construction industry, and the design professions. (See appendix for compliance with the LEED rating system.)

The committee also used computer design tools to predict building performance and rank green building concepts in order of importance for this project. Computer design tools were used in the analysis of green building concepts below. These tools included:

Climate Consultant 2.0. A building must perform well in a given climate. In this case, the climate reaches temperature extremes in the winter and summer months. In addition, summers are particularly humid. Climate Consultant 2.0 was used to define design strategies which work in the Omaha climate. This study can be done at the beginning of any project with climate data. Strategies suggested by Climate Consultant were consistent with those tested by the Energy 10 evaluation program.

The Energy IO performance evaluation program. Building performance refers to the efficiency with which the building performs its intended functions. With the computer design tool Energy 10, ENSAR Group was able to recommend rmderate and advanced measures to improve building performance in terms of energ) efficiency. Energy 10 also ranks design options in order of effectiveness and calculates energy and cost savings.

Page 18 THE OMAHA GREEN BUILDING INITIATIVE

Other performance criteria. Objective experiential measures such as minimizing water use or durability of materials were also used to test performance.

The application of the computer evaluation tools indicated that insulation of the building envelope or exterior walls would be effective. Climate Consultant 2.0 confirmed that the project should consider maximizing natural ventilation through such devices as operable sash and internal ventilation stacks. ENSAR Group's analysis ranked the relative effectiveness of various energy conservation techniques for this project in the following order: insulation, high performance glazing, daylighting, thermal mass, and passive solar.

The Committee identified applicable green building concepts which distinguish this project from a conventional building renovation. These concepts included treatment of the building envelope, daylighting, natural ventilation, water conservation, material selection, and construction waste management. Most of these concepts were found to be directly applicable to the Pull- man Hotel project. BUILDING ENVELOPE ENHANCEMENTS. Analysis by The committee also addressed the relationships among ENSAR group of the Pullman Project concepts. Air quality, for example, is related to natural indicates that insulation and improved ventilation, low levels of VOCs (volatile organic com- glazing are the most effective means of improving the energy conservation pounds) found in some building materials, mechanical performance of the building in the Omaha systems, appliances operated in the building, and climate. Recommended wall insulation landscaping. levels range from R-15 to R-22. Building Insulation and Envelope

Based on the Energy 10 analysis, the Committee strongly recommends the insulation of the exterior brick walls. Because the building currently lacks insulation, this action offers the single greatest im- provement in energy efficiency. Existing windows should be replaced with high performance windows in the existing openings. The design of these windows

Page 19 THE OMAHA GREEN BUILDING INITIATIVE

should conform to the appearance on the north and west elevations to the original windows in historic photographs.

Day Zig ht ing

Daylighting is reliable at the perimeter of the building. The small floor area of the building allows daylight to reach most of the useable space, making daylighting an effective design solution. Energy efficient lights are recommended in conjunction with lighting sensors and controls for interior spaces and evening use. In addition, the detailed building design should consider the use of indirect daylighting techniques such as light shelves, which direct reflected natural light further into the space.

Passive Solar Design

Passive solar design and thermal mass have little effect on building performance according to the Energy 10 analysis. However, increasing the window area on the south elevation provides more daylight and direct sun in the residential space. It is also important to insure solar access to the building, previously blocked by an adjacent building on the south. Location of the eco-park on the corner lot would allow sun to ' reach the building. Solar access must be provided if the building is to perform as

7 predicted.

Natural Ventilation

The effectiveness of natural ventilation is difficult to predict and has been a subject of considerable debate. The committee considered the construction of ventilation stacks in the building interior. These stacks were placed opposite north and south facing windows to create cross ventilation in every space. Based on a minimum interiodexterior temperature differential of 5 degrees, the ventilation stack should provide a rate of 6 air changes per hour at the ground floor with a stack to the roof. The stacks do not reduce the peak cooling load, which is used to size the cooling equipment, but increase the length of time that natural ventilation can be used. This in turn reduces the annual expenditure of energy for cooling purposes. Reduced use of air conditioning reduces the harmful effects of refrigerants and the generation of greenhouse gases which cause ~ global warming. ~~ ~

Ultimately, the vertical stacks were not incorporated into the final design analyzed here. - Because of the building's relatively small floor plate, the elimination of additional leasable space proved uneconomic. However, the development of stacks is a logical measure to consider in other adaptive reuse projects, particularly warehouse conver-

Page 20 THE OMAHA GREEN BUILDING INITIATIVE

NATURAL VENTILATION. The Green Building design committee studied the innovative use of ventilation stacks to reduce reliance on mechanical ventilation in the project. The current design does not propose the use of stacks, primarily for economic reasons in a small floorplate building such as the Pullman. However, the technique has signifiant applications to projects involving buildings with large floorplate buildings, such as residential conversionsof warehouses.

sions with large floor plates and a low ratio of exterior wall to building area. In addition, the use of ventilation stacks is more logical using an alternative plan providing four units per floor.

Mechanical Systems

Three alternative mechanical systems for heating and cooling were evaluated in terms of efficiency and compatibility with other proposed design strategies. These systems included ground source heat pumps, fan coil units, and air to air heat pumps.

The following chapter considers these alternative systems in more detail. Of the three systems considered, the ground source heat pump has the highest efficiency. However,

because the land area for this system is not presently available and ground source ~ technology is relatively untested in this area, the Building Design Committee recom- ~~ mended the use of an air to air heat pump system. This system is very efficient and is

compatible with a design for natural ventilation. It is especially applicable in building __ designs that utilize stacks for natural ventilation. The ventilation shaft can act as a vent stack during 6 months of the year and act as an air supply duct when the air to air heat pump is operating. In addition, location of the condensing units in the basement will protect them from extremely cold temperatures. This could eliminate the need for a back up heating system normally required in this climate. Page 21 THE OMAHA GREEN BUILDING INITIATIVE

Chapter Four GREEN BUILDING SYSTEMS AND MATERIAL SELECTION

THIS CHAPTER CONSIDERS DESIGN ISSUES THAT DETERMINE MA- JOR COMPONENTS OF GREEN BUILDING DESIGN. These considerations distinguish the Green Building concept from conventional adaptive reuse projects in the Omaha market and provide important applications to other projects. They include:

1. Design features to maximize energy efficiency. 2. Mechanical system options. 3. Construction waste management. 4. Material selection.

The Pullman Hotel is a four story building plus basement of uninsulated masonry construction. Most windows are single-pane glass with wooden sash. The building currently lacks a cooling system for the upper residential floors and radiators located beneath the windows provide heating. The street level commercial area is heated and cooled by individual forced air systems. The building is elongated in a north-south direction with a majority of the windows on its east and west facades. The north and west facades have significant architectural value. In order to conform to the Secretary of the Interior's Standards, an important design principle, these facades will not change substantially in appearance. The building is located in Omaha NE which has a summer design temperature of 94" F DB and 76"F WB, and winter design temperature of -8" E

Goals

In planning the project, the Green Building Council's major energy efficiency goals are to:

Meet a majority of the LEED Green Building Rating System Criteria, and Satisfy the LEED criteria as cost-effectively as possible.

The LEED Green Building Rating System criteria address the following energy- related issues:

1. Indoor air quality 2. Natural ventilation 3. Renewable energy

Page 22 THE OMAHA GREEN BUILDING INITIATIVE

4. Energy efficiency 5. Daylighting 6. Waste heat recovery

The Green Building Council employed Ove Arup & Partners and ENSAR Group, Inc. to assist with design and evaluation of various green building systems. As a general principle, the Building Design Committee focused on the most cost-effective design, allowing green building construction and renovation techniques to be competitive with non-green building methods. Based on the analysis of systems with respect to this general principle, the building can feasibly meet or exceed the LEED Green Building Rating System Criteria for indoor air quality, renewable energy, energy efficiency, and daylighting. Because of Omaha’s climate characteristics, the building can only partially meet the natural ventilation standards. Finally, installation of a waste heat recovery system does not appear to be cost-effective because of the proposed occupancy of the bui 1ding.

Green Building Systems and Design Strategies

Probably the easiest and most cost effective method for increasing the energy efficiency of the Pullman Hotel is to increase the thermal resistance of the building envelope. Both consultants agreed that increasing the insulation within the wall and roof cavities and installing thermal resistance windows would both greatly reduce the energy consumption and increase the thermal comfort of the occupants. They found that raising wall and roof cavities to R-24 and R-30ratings respectively and installing windows would exceed the ASHRAE Standard 90.1 (Energy Efficiency Standard). By exceeding the ASHRAE Standard 90.1, the project would satisfy the LEED Green Building Standard Criteria for energy efficiency, Adding insulation and improving the window system is very cost effective and does not compromise the historic facades of the building. ENSAR concluded that the improved insulation and windows would reduce energy use by approximately 21%.The increased thermal resistance of the building envelope would increase the thermal comfort of the occupants by reducing the temperature swings within the building. In addition, insulation and new windows would also decrease the amount of air infiltration that in turn leads to drafts.

ural Ventilation..

Indoor air quality and natural ventilation go hand in hand. In most cases, introducing more outside air into the building produces better indoor air quality. The most direct way to increase natural ventilation is to provide every room with an operable window, providing occupants with control over the amount of outside air. The materials used in Page 23 ~ ~~ THE OMAHA GREEN BUILDING INITIATIVE construction and the materials placed in the building also affect indoor air quality. This problem will be addressed in the materials section of this report.

The committee also investigated supplementing operable sash with other techniques to increase natural ventilation. Ove Amp & Partners recommended the use of stacks with venturi cowls mounted at the top of the stack. The venturi cowls create a negative pressure at the top of the stack with the help of a moderate wind. This negative pressure would suck out the hot air in the interior of the building through the stack. The removal of the hot air from the interior of the building would then allow more cool air to flow through the windows and into the building. The venturi cowls and stacks would still operate without wind; however, operation would depend on the buoyancy effect of hot air. The use of shafts for natural ventilation also depends on the floor plan. The plan should provide air with a relatively clear path for entering and leaving the building. Air entering at the bottom of the window would have a tendency to rise as it crosses the room moving toward the ceiling height grill of the ventilation shaft- This air flow is not obstructed by low partitions or furnishings.

Ultimately, the final plan did not include the use of ventilation stacks. In a building with a relatively small floor plate, the stacks substantially affected the economic and functional efficiency of the building. Stacks may be effectively employed in buildings with a large floor plate to improve interior ventilation; this is applicable to many of Omaha’s larger warehouses that are being considered for adaptive residential reuse.

Extremes in Omaha’s climate prevent the use of natural ventilation on a year-round basis; therefore, an auxiliary mechanical system is required to bring in the minimum outdoor air at extreme outdoor air temperatures. The LEED Green Building Rating System Criteria calls for the building to be naturally ventilated with passive heating and cooling for eight months of the year. Ove Amp & Partners concluded that natural ventilation can be effectively employed for only six months of the year. As a result, a building in Omaha can only partially meet the LEDcriterion.

Renewable energy sources do not involve depletion of finite resources, but utilize forces that are natural within the environment. Some of the renewable energies are solar (both active & passive), wind, and hydropower. The Green Building Council considered several forms of renewable energy, and concluded that the most realistic source of alternative energy is solar. Hydropower was not considered due to the location of the site. While wind power appears promising, Omaha’s winds lack the streno& and consistency for significant power generation.

Page 24 THE OMAHA GREEN BUILDING INITIATIVE

Photovoltaics (Active Solar)

The Pullman Hotel provides promising possibilities for the use of photovoltaics. Ove Arup has calculated that filling the roof area with photovoltaics would generate enough power to supply one floor, or 20% of the entire building. Initial capital costs and programmatic decisions, such as the use of the roof for other purposes such as a garden, will prevent full use of this area for photovoltaic cells. Available roof area for photovoltaics may be about 40% of the total roof area, able to generate 8% of the total building usage.

The most effective way to use photovoltaics is to connect them through an invertor to the grid and use two-way metering. This would allow the Pullman Hotel to sell excess power to the utility company and eliminates the need for an expensive storage system.

I. Passive Solar

Passive solar heating uses radiation from direct sun on the interior floors and walls to heat the structure. The use of passive solar energy requires changes to the south facade of the building, including the addition of windows. ENSAR Group recommended increasing south facade window area from 7% to 14%. In addition to providing direct solar gain that can also be shaded effectively when it is not needed, the increased south faqade window area will provide additional daylighting along the south wall.

The south faqade was once obstructed by an adjacent building; as a result, this facade is probably not considered historically significant for a certified rehabilitation project. Generally, the Nebraska State Historical Society, the designated State Historic Preserva- tion Office, permits penetration of non-historic facades, subject to specific review, if:

1. The new penetrations are consistent in form and rhythm with building openings original to the building.

2. A design method or symbol is employed to distinguish new openings from historic openings.

The LEED Green Building Standard Criteria requires 10% of the total building energy to come from a renewable source. The Building Design Committee feels that the Pull- man Building can exceed this requirement with the use of photovoltaics and passive solar. However, the capital cost of installing photovoltaics probably requires a supplemental demonstration grant source.

Daylighting Page 25 THE OMAHA GREEN BUILDING INITIATIVE

Daylighting as a green building strategy makes maximum use of natural light to illumi- nate the building’s interior, minimizing use of artificial lighting. Daylighting is only effective within about 20 feet of an exterior window. The Pullman’s small, relatively narrow floor plate is optimum for daylighting strategies, providing nearly all spaces with access to a window. Daylighting helps the energy efficiency for the Pullman Building in two ways. First, it reduces the amount of electricity needed to light the interior of the building. Second, since electric lights emit waste heat, the reduced amount of lighting also reduces cooling loads.

Daylighting can be enhanced at the Pullman Hotel in several ways. Increasing the number of window openings on the south face of the building allows more sunlight to enter the building and increases passive solar use. The use of light shelves mounted near windows may help reduce the glare and throw light farther into the interior of the building.

An effective daylighting system is enhanced by an efficient control system. Such a system continuously controls the artificial lights to maintain the proper lighting levels. This system also turns off the lights when the room is unoccupied. ENSAR Group calculates that daylighting can bring an annual cost saving of approximately 14% .

Building Planning for Conservation

The strategic placement of functions in the building can also improve energy efficiency. For example, the street level office area, with its lighting and equipment, produces significant quantities of heat. Therefore, locating these areas on the north side of the building uses this potential waste heat to supplement the building’s HVAC system. In addition, placing office spaces on the cooler, north side of a mixed use building reduces peak summer cooling loads. On the other hand, location of residential uses with southern exposures increases benefits from passive solar heating. Further, these spaces are usually not occupied at peak temperatures in the mid-afternoon during the summer months so cooling energy is saved.

Wall locations can also affect energy efficiency by enhancing air circulation and daylighting. Airflow should be allowed to enter the building and exit the building with little interference. The floor plan for the Pullman Hotel recommends these planning principles to increase overall building efficiency .

Summary

The strategies most appropriate for design of the Pullman Hotel as a green building include:

Page 26 THE OMAHA GREEN BUILDING INITIATIVE

1. Increasing the thermal resistance of the building envelope by installing insulation and ~- energy -effi ci ent windows .

2. Maximizing natural ventilation by installing operable sash and minimizing full height ~ wall obstructions that inhibit air flow.

3. Utilizing roof-mounted photovoltaic cells to the maximum degree permitted by economic and programmatic considerations.

4. Increasing window penetration on the building’s south faGade to increase use of passive solar heating.

5. Using enhanced controls, and additional window openings to increase opportunities for daylighting. Light shelves may also be used to both shade light and distribute it more effectively around an interior space.

~ 6. Employ planning criteria to maximize energy efficiency by locating office uses on the north side of the building.

7. Use energy efficient light fixtures and plumbing fixtures that minimize water usage.

Page 27 THE OMAHA GREEN BUILDING INITIATIVE

Mechanical Systems

To make any of these methods, techniques, and strategies work, they must be integrated with the building’s functions and the building’s mechanical system. This section evalu- ates a1 temative mechanical systems and examines their applicability to green building design for the Pullman Hotel.

The Building Design Committee and its consultants considered an array of mechanical systems and concluded that the best candidates for use in the project are:

1. Fan Coil Units with an air-cooled or water cooled chiller & a high efficiency boiler. 2. Ground Source Heat Pump System 3. Air to Air Heat Pump system with auxiliary heating.

Each system will include an exhaust system to ventilate toilet areas. Each system will also deliver outside air to the occupied spaces as prescribed by ASHRAE 62. The follow- ~ ing discussion will describe the systems and consider their advantages and disadvantages.

Fan Coil Unit System

Description: In this system, fan coils will be mounted underneath selected windows. An opening in the exterior wall will allow the minimum outside air into each unit to fulfill the ASHRAE 62 requirement. The fan coil unit will be equipped with heating and cooling coils. Chilled and heated water will be supplied to each unit from a chiller and boiler located in the basement. The chiller will probably be air-cooled unless well water is available and sufficient, in which case the chiller will be water-cooled. The boiler shall be highly efficient to allow for possible venting through the wall. Through-the-wall venting will eliminate the boiler stack, which is expensive and requires floor space. Each fan coil unit shall be metered for chilled water and heating water usage. The meter will allow for individual billing of each tenant.

Advantages: Some advantages of this system are ease of installation and a proven track record. Ease of installation comes from the fact that these fan coil units require no ductwork or chases. Fan coil units only require chilled water and heating water to be piped to them. Fan coil units have been in use for approximately fifty years, minimizing potential surprises or unforeseen costs. In addition, fan coil units emit relatively low levels of carbon dioxide, sulfur dioxide, and nitrogen oxides in comparison to other systems.

Disadvantages: One of the disadvantages of this system is chiller inefficiency. The chillers are inefficient when running at part load. If the lower level of the building were used for an inhabited space, noise and vibration might also pose problems. This is mini- Page 28 THE OMAHA GREEN BUILDING INITIATIVE mized by the storage and parking uses currently programmed for that level. Since the load of this building is 30 tons, the only chiller available will be a reciprocating compressor chiller. Reciprocating compressor chillers, in particular those that are air-cooled, can also be noisy and vibrate. If an air-cooled chiller is located in the mechanical room, that space will require a high ventilation rate. Another potential disadvantage is that small openings required in the exterior wall at each fan coil unit could affect the historic appearance of the north and west building elevations.

Description : In this system, heat pumps will be either mounted in a closet or mounted in the corridor ceiling void. Outside air will be delivered to each heat pump via an outside air fan. The heat pump is responsible for heating and cooling each space. Condenser water will be pumped to each heat pump. A well field with vertical wells will be located underneath the parking lot and will act as a heat sinWsource for the condenser water.

Advantages: Because the heat pump is a self-contained heating and cooling unit, a chiller and boiler and associated equipment are not required. Heat pumps are highly efficient and energy can be transferred from one heat pump to another via the condenser water.

Disadvantages: The well field will require approximately 5,000 square feet in site area, depending on specific site and subsurface conditions. This space may not be available on the Pullman’s constrained site and would require a long-term cooperative agreement with another property owner. In addition, heat pumps are a new technology and some system problems may occur.

-- Heat Pumps

Description: This system will consist of air-to-air heat pumps, installed in a manner similar to the ground source heat pumps. Outside air will be delivered to the air-to-air heat pumps in the same fashion as the ground source heat pumps. Each of the air-to-air heat pumps will be responsible for heating and cooling each space. An air-to-air heat pump system may require supplemental heating. This can be accomplished by perimeter heating with fidtube units mounted under selected windows. The boiler and associated equipment will be located in the basement. Auxiliary heating may not be required if condensing units are located in the basement and the room is heated.

Advantages: The air-to-air heat pump system is highly efficient and can be installed at a relatively low capital cost, compared to ground source heat pump systems. The air to air heat pumps are highly efficient and may have a utility incentive rebate associated with them. Page 29 - THE OMAHA GREEN BUILDING INITIATIVE

__- Disadvuntuges: A primary disadvantage of the system is low heat output in extreme cold

weather. The condensing units will be located in the basement. Sound insulation and a ~ buffer zone (which may be provided by the recycling center) may be needed to prevent ~ equipment noise from interfering with other building uses; however, these problems are minimized if the lower level is used principally for storage. In extreme cold weather, the air-to-air heat pumps may be inadequate for heating. However, auxiliary heating may not be required if condensing units are located in the basement and are protected from extreme cold.

The Ove Arup report containing analysis of these systems is included as an appendix to this document.

GROUND SOURCE HEAT PUMP. This innovative system was considered for the Pullman Building. Howevec because of its site requirements and new technology, it was not selected for this rather small development. Page 30 THE OMAHA GREEN BUILDING INITIATIVE

of the three systems discussed in the above paragraphs, probably the “greenest ‘‘ of the systems is the ground source heat pumps. It has the highest efficiency of the three systems. The ground source heat pump system is also the most innovative as it uses the earth as a heat sink and source. The system is also the quietest and requires no additional or auxiliary system installation. However, the required land to support the ground source system is not presently available. In addition, the technology is relatively untested. Therefore, the Building Design Committee does not recommend the use of the ground source heat pump at this time.

Committee members completed a comparative life-cycle analysis of the two remaining systems, fan coil units and air-to-air heat pumps. This comparison led to the following conclusions:

Economic Costs. The economic costs of the two systems over a 20-year life cycle are relatively the same for the two systems. A fan-coil system has a life cycle cost of $358,486,compared to $351,605for the heat pump system. The initial installation and ongoing operating costs of the fan-coil system are higher for fan-coils ($205,479 versus $148,242 on a life-cycle basis), while the cost of energy (electricity versus natural gas) are, at least at present, higher on a life-cycle basis for the electrically powered heat pump ($162,747 to $112,492). Water costs are equal for the two systems at $41,000.

Environmentul Costs. Environmental emissions appear to be substantially higher for heat pump systems than for fan-coil systems, based on the type of fuel being used to produce energy. On a 20-year life cycle basis, emissions are about 76% higher for the heat pump system than for the natural gas fired fan coil system. These calculations are based on the Building Life Cycle Cost Program (BLCC), which uses national averages to determine emissions for generation of electricity.

The Building Design Committee initially recommended the use of the heat pump as most compatible with the ventilator stack system of natural ventilation. The stacks would be used as air intakes, reducing ducting needs. On the other hand, the environmental impact calculations of the two systems, based on national averages for energy production, may lead to the use of a fan-coil system. Another possibility is the use of the photovoltaic array to provide electricity for the heat pumps. This would alleviate concerns about the emissions produced by other sources of energy.

Page 31 THE OMAHA GREEN BUILDING INITIATIVE

Construction Waste Management

Management of construction wastes creates a significant environmental impact that should be considered in the design and execution of green building projects. Nationally, over 25% of the volume of waste in municipal landfills is the result of construction. Waste management is particularly important on remodeling and rehabilitation projects such as the Pullman. The impact of waste management programs on construction cost can vary from contractor to contractor. Contractors who normally practice waste management techniques and recycling have channels for selling recycled materials and can realize savings from these practices. On the other hand, contractors who are new to waste management techniques may experience higher costs, which can also affect the project.

On the Pullman project, effective waste management techniques should be incorporated into construction. The contractor should prepare and implement a Construction Waste Management Plan which:

1. Identifies materials to be recycled and landfilled. 2. Identifies potentially hazardous wastes and defines disposal methods. 3. Locates sorting and waste storage facilities on the site plan. 4. Documents subcontractors plans for waste management.

Materials

The materials that are used in a building have a major impact on both the external environment and the quality and performance of the project itself. The Green Building Council used the following principles to guide its consideration of alternative materials:

Environmental impact. Appropriate materials should minimize environmental impact during extraction, manufacturing, transportation and installation.

Impact on building occupants. Selected materials should maintain a healthy interior environment for residents of the building. In addition, materials should be attractive and designed for a good reception in the marketplace.

Post material use. Appropriate materials should be reusable or recyclable.

Listed below are criteria that were used to guide the research of “green material” by members of the research team and to assist with material selection.

Page 32 THE OMAHA GREEN BUILDING INITIATIVE

.- Production

Products were favored which:

Contained recycled content material, including post-consumer content, waste from outside the production process and waste from the production floor.

Include renewable resource material produced from accredited sources using strict harvesting practices and controls. Manufacturing processes which have been updated to include energy eficient practices and processes were also considered.

Products whose production processes included low emission practices, where measures have been taken to reduce gaseous liquids, solid waste and toxic waste from the waste stream and where the above practices exceeded regulations. .. Packaginz ana‘ Shgqmnp

Products were favored which:

Were produced in areas within the Midwest region in order to reduce energy expendi- tures for transportation. LEED establishes a regional radius of 350 miles to certify “local production.”

Used packaging processes which utilized renewable resources and recycled content material, or minimized use of packaging.

Installation and Use

Products were favored which:

Reduce hazards by avoiding special handling procedures or protective equipment during installation.

Minimize or avoid the use of volatile organic compounds (VOC’s).

Are chemically stable materials, or are manufactured and installed in a way that reduces off-gassing or harmful particulates. - Are longer lasting and more durable, increasing the material’s life expectancy.

Require less post-maintenance cleaning or care through the use of solvent-based or phosphate materials.

Page 33 THE OMAHA GREEN BUILDING INITIATIVE

5. Consideration was given to the recovery of material for reuse or recycling purposes. A demolition and waste management program is recommended with some of the recovered materials reused in the renovation.

Application of the evaluation criteria led to selection of the following materials for the Pullman Hotel green building project. Cost estimates were then built on these material selections.

CEILING TILES Recommendation: Use of Perlite Tiles

Perlite tiles are manufactured from perlite, clay and liquid glass. They avoid the use of man-made mineral fibers, which some experts associate with “Sick Building Syndrome.” This material has zero flame spread, zero smoke development, and zero fuel contributing characteristics. Since it is made from inert materials, it does not encourage the growth of fungus or bacteria. It may be used in high humidity applications without sagging. Re- cycled panels may be used as vermiculite in landscaping applications.

Manufacturers of MMF ceiling tiles have been pursuing waste reclamation programs that typically do not involve post-consumer product. For the most part, mineral wool and waste paper products from other sources are used in acoustical materials. Depending on the product, manufacturers advertise up to 80 percent minimum recycled content. Efforts are growing in office applications to make the manufacturer of a product responsible for its removal from the job site. Ceiling tiles should be an exemplary product in this regard.

IRESILIENT FLOORING - Sheet Flooring Recommendation: Eliminate Use of PVC

According to the AIA Environmental Resource Guide, 60 percent of all PVC is used in building construction. Yet many environmental advocacy groups have identified PVC as one of the most dangerous materials in the environment. While most experts concede that PVC in its finished state is relatively inert, many contend that the manufacture and disposal of this material introduces many hazardous chemicals into the environment. Some of these chemicals are known carcinogens and hormone disrupters, including dioxins and PCB’s. An additional health care problem exists when PVC is incinerated as part of medical waste disposal. Linoleum or rubber should be considered as substitutes to vinyl flooring.

Page 34 THE OMAHA GREEN BUILDING INITIATIVE

II RESILIENT FLOORING- Linoleum Recommendation: Use of linoleum instead of sheet vinyl

Linoleum is one of the most environmentally sound flooring materials because it is usually manufactured from renewable resources. Since the oxidation of linseed oil can produce a strong odor in fresh material, special IAQ criteria should be followed during installation in occupied facilities. There are no significant recycling efforts for linoleum; however, as a biodegradable material, it can be disposed of in landfills.

II CARPET Recommendation: Maximum recyclable content

The project should utilize carpet that maximizes recycled content materials and that utilizes antimicrobial agents. Some manufacturers maintain lease agreements which provide for installation and ongoing maintenance. This maintenance agreement extends lifetime performance by maintaining and selectively replacing work sections of carpet. It also provides for reclamation and recycling of the carpet upon replacement.

II CONCRETE Recommendation: Use concrete with fly ash or recovered material where possible.

Using fly ash, recycled concrete, recycled glass, or other materials reduces the amount of virgin material required and decreases waste going into the landfill. The amount allowable will vary for each specific application. Use of precast products instead of poured-in- place concrete reduces environmental impact at the construction site.

=ADHESIVES Recommendation: Use water-based adhesives with no, or low VOC.

It is usually preferable to consider alternative methods to adhesives for installation of materials. An example is tacking rather than gluing carpet. Typical adhesives contain VOCs that off-gas. In many cases, the adhesive off-gasses more than the product being secured. In addition, the compatibility of the adhesive and the secured materials should be confirmed before installation.

II WALL FINISHES Recommendation: Gypsum Drywall

Gypsum drywall consists of two primary components: gypsum and kraft paper. Gypsum, a form of calcium sulfate, is a natural mineral. In addition, the use of recovered gypsum or by-product, such as flue-gas gypsum, is increasing. From ten to fifteen percent of the volume of these recycled materials is being used in the manufacturing of new drywall. Page 35 -- - __- THE OMAHA GREEN BUILDING INITIATIVE

Demountable drywall systems, using drywall clips, allow for easy removal and reuse.

The kraft paper used as a backing is one hundred percent recycled paper. It is recommended that dry-mix joint compound be used instead of ready mix products. The dry-mix products have less additive concentrations and packaging waste and require less energy in shipping. Joint tape, like the kraft paper, should contain a high percentage of recycled Paper.

Gypsum drywall is also the most economical material to use for wall partitions and finished surfaces. The cost of gypsum drywall is about 40 to 50 percent less than that of alternative products such as plaster and lath or wall panel systems.

H PAINTS Recommendation: Locally manufactured, low VOC paints

Paints containing volatile organic compounds (VOCs) contribute to indoor air pollution. ApRropriate selections include paints with either low or no VOC levels. The final choice of paint must balance cost with the marginal benefit of alternatives with low or zero VOCs. A local paint manufacturer is able to deliver a low VOC paint at half the cost of a zero VOC product. Choosing a local manufacturer decreases the use of energy during transportation and also patronizes a local business. Another green alternative is to use paint from a local paint recoveryhecycling program.

INSULATION Recommendation: Blown cellulose

Among the most recent entries to the insulation market is blown cellulose, manufactured from both post consumer and post-production newspaper. This product does not use virgin fiber pulp in its production. The cellulose fibers are combined with an inert fire retardant, usually borate and an acrylic binder. Cellulose has equivalent and usually higher R-values compared to fiberglass insulation and avoids health risks associated with installation. Application is most often accomplished by spraying materials directly into wall and ceiling cavities. A one to two day drying period is recommended prior to installation of drywall or wall covering. Cellulose is currently the most common alternative to fiberglass batt insulation and is available in most markets.

SHELVING AND STORAGE SYSTEMS Recommendation: Steel shelving

Industrial steel shelving has become a major contender in the warehouse to loft renovation arena. The shelving is very easy to install and is manufactured in standard dimensions. The shelves are available in steel, aluminum, or stainless steel versions. Connec-

Page 36 THE OMAHA GREEN BUILDING INITIATIVE

__ tors and supports are of galvanized steel. The steel shelf version is manufactured using recycled steel. The units can be installed in both kitchens and bath areas.

These units also accommodate built-in appliances and sinks with little alteration. Steel outperforms ~ conventional cabinet construction (often using pressed particle board) for product life, air quality, and material reuse or recycling. Conventional particleboard cabinets have an average life span of ten to twelve years; they also off-gas formaldehyde and other VOCs associated with the manufacturing process. Current plywood and particleboard cabinets have virtually no reuse or recyclable value.

DOORS AND FRAMEWORK Recommendation: Steel and wood trim from sustainable forests

Steel doors are fabricated from cold rolled steel or hot dipped galvanized steel. They are then rein- forced, stiffened, sound deadened and insulated with an impregnated kraft honeycomb core. The core is completely filled and laminated to the inside faces of both panels. Finished painted doors arid

frames should be cleaned, phosphatized and finished with baked on rust inhibiting, water-based ~ paint. These doors are superior in strength and durability to wood doors.

Estimations of recycled steel content in new doors and frames ranges anywhere from twenty-five to thirty-five percent. Recycled steel requires less energy to manufacture than virgin steel. When one ton of steel is recycled, 2,500 pounds of iron ore, 1,400 pounds of coal, and 120 pounds of limestone are conserved. These factors are important to consider when evaluating material and their impact on the environment.

Floor and other trim should be manufactured from wood that is harvested from sustainable forests.

SOURCES:

Environmental Building News .. Rocky Mountain Institute, AnSustainable Bulldln,.0 Sustainable Design Guide HOK .. National Audubon Society and Croxton Collaborative, Audubon House: Ruuthe Eneua le. Etliergy-Effi&nt Office. New York John Wiley and Sons, Inc., 1994. American Institute of Architects, EnvironmentalResource.. Guide US Green Building Council, J eadmvirov0 U

Page 37 THE OMAHA GREEN BUILDING INITIATIVE

Chapter Five ECO-PARK: THE PULLMAN BUILDING IN THE URBAN LANDSCAPE

THE PULLMAN HOTEL CONCEPT EXTENDS THE PHILOSOPHY AND PRIN- CIPLES of Green Building design to the external urban environment. The idea of a sustainable environment clearly does not stop at building walls. Indeed, given the large amount of urban land used for the storage of automobiles, in turn increasing urban runoff, reducing permeability of water into the soil, and affecting the urban microclimate, site design becomes a critical component of green building development.

The Pullman Hotel site has important constraints for outdoor space development. Its limited site provides few opportunities for outdoor landscaping. In addition, programmed uses for the project generate a demand for substantial parking: a minimum requirement of 21 to 30 stalls to accommodate a 21-unit apartment building and a demand for 16 to 20 stalls generated by street level commercial and office development. As important, the Pullman site does not control land to the east and north, which will be essential to provide adequate adjacent parking and green space development. This property is part of the Burlington Station ownership and its long-term availability will ultimately be bound with the fate of that historic structure. The concepts included here assume a unified redevelopment project that combines the adaptive reuse of the Burlington Station and the Pullman Hotel with a shared parking facility serving the needs of both projects. This parking lot must also serve the needs of Joe Banana’s restaurant on the west side of lUhStreet, if that existing parking lot is used for urban park purposes. The Green Building Council strongly supports conceiving of the Pullman project as part of a unified development concept in this strategic location on the lP Street Corridor.

The work of the Green Building Council’s Landscape Committee identified two areas for concentrated work: an Eco-Park, addressing the ground level environment around the Pullman Hotel; and a rooftop garden, utilizing the roof as outdoor space for the benefit of building occupants.

The Eco-Park: Concept and Adaptation

An Eco-Park uses natural cycles to create a self-sustaining outdoor green space. It provides an opportunity for cultural and ecological interaction, education through experience, and satisfaction of the long-term needs of the surrounding land and people. This concept of an Eko-Park is compromised to a significant degree by the selection of the Pullman Hotel site, which offers little opportunity for development of a full-scaled Eco- Park. Therefore, the committee adjusted its programming and concept to the challenging problem of designing a “green space’’ that meets the functional needs of a dense urban Page 38 THE OMAHA GREEN BUILDING INITIATIVE

PULLMAN BUILDING SITE ANALYSIS. The Pullman is located in a dense urban setting at the 10th and Pacific commercial cluster and immediately adjacent to the city's historic railroad depots.

environment. As a result, the project addresses critical issues of parking lot design, streetscape development, and urban parks. The result is a new, highly applicable form of Eco-Park that demonstrates a design solution with limited spatial resources using strict criteria.

Programming the Eco-Park

~~ The Landscape Committee devised standards for development using the above definition

and adaptation of the Eco-Park concept as a guide. The following criteria are a checklist - providing a baseline of standards to guide the design process. Because these criteria were developed early in the process, they describe ideal situations that may be compromised by space, material availability, environmental and climatic characteristics, funding, or the local context of the site. However, they represent a process that should be considered in the site design of all projects. Page 39 THE OMAHA GREEN BUILDING INITIATIVE

The criteria fit into three categories describing the functional, structural, and experiential aspects of the proposed landscape. Functional aspects address ecological processes necessary to support the biological health and well-being of an eco-park in a highly urban setting. They also address the lifestyles, activities, and functional needs of potential users. Structural elements include construction and plant materials considered desirable for use in an eco-park. Experiential elements address the user experience in an urban eco-park, based on the local context and nature of park users. They also include the aesthetic goals of the space.

Ecological Criteria

Provisions for wildlife Energy efficiency Efficient irrigation and water use Stormwater retention, detention, and reuse Stormwater cleansing with first flush wetlands treatment Natural fertilizers without chemical treatment Increased oxygen and decreased carbon dioxide levels Increased shade and lower microclimatic temperatures for site and building

Social and User Needs

Links to surrounding community and riverfront greenway system Education and demonstration Site lighting with solar and alternative energy sources Minimal maintenance requirements On-site sewage treatment Composting space Collection and reuse of gray water Recycling facilities Outdoor spaces to accommodate cafk seating, leisure, and conversation Space for residents’ food production Adequate parking to serve Pullman Hotel and Burlington Station needs. Program recommends 85 regular and 4 handicapped parking stalls Accommodation of site grades Auto drop-off for accessible building entry Caf6 access to upper terrace garden

Page 40 9

Hardscape Components

Locally available materials Reuse of site demolition materials Materials with recycled contents

0 Permeable surfaces where possible Materials with low reflectivity Materials which are non-toxic in application and construction Materials with low embodied energy in fabrication, installation, and maintenance

Softscape Components

Native plants Naturalized, non-invasive plants Organic fertilizers and pest treatment

Character

Open and intimate spaces Green, aesthetically pleasing outdoor room Provision for birds and butterflies Reduced apparent retaining wall heights on south and west perimeters of lower parking area Prevention of “sea of concrete” - breaking paved areas into smaller parts Varied opportunities for shade and sunshine

Experience

Sounds of water to mask street noise Places for people-watching Areas for vegetable gardens Rooftop access for gardening, sunbathing, city viewing

Eco-Park Design Solutions

Components of the Eco-Park site design include:

Park& lor, The proposed parking lot design includes 89 stalls (85 conventional stalls, 4

Page 41 THE OMAHA GREEN BUILDING INITIATIVE

handicapped accessible stalls) with entrances from 10* Street on the west and Pacific Street on the south. Parking north of the Pullman continues down to the main parking level at the approximate basement floor level of the hotel. Parking modules are divided by intermediate areas landscaped as wetlands. Conventional parking lots have continuous paved surfaces, with landscaped areas defined by curbs. In this design, curbs are not used at the edge of landscaped areas and storm drainage is directed into the wetlands area. This reduces off-site runoff and utilizes the potential of wetlands to cleanse drainage.

ed r@ --qf way- Deciduous street trees will be established along the lehStreet building frontage and along Pacific Street. Trees are established in planting beds, providing trees with adequate space for root growth. Trees and canopies along 1W Street will

~ ECO-PARK DESIGN. A major feature of the Bo-Park concept is a parking lot design that manages urban run-off by providing wetlands areas between parking modules. Titis solution can be replicated in suburban sem'ngs, where projects involve large masses of parking. Page 42 cut direct solar gain from late afternoon sun. On the other hand, plantings are placed to avoid interfering with south and east sun on the building’s other principal exposures.

@per Terrace GarkAn existing parking lot would be used as a small urban park under the Eco-Park concept. This provides an upper terrace featuring a paved surface which nevertheless supports maximum permeability. This surface may utilize a stabilized surface such as “grasscrete” pavers - sectional pavers that are perforated to permit growth of grass. This area may include a seating area to serve a caf6 tenant in the south half of the Pullman Hotel. A series of terraces is used to moderate the change in grade and reduce both the scale of retaining walls and storm run-off. A parallel stairway is used to link the parking lot with the 10* Street level.

Rooftop Garden

Existing Conditions

The concept of site landscaping on this urban parcel also includes a roof garden to reduce urban heat, provide an aesthetic benefit to occupants and viewers, and help cool the building by reducing heat gain from the roof. The existing building roof is about 67 feet from east to west and 87 feet from north to south. It is divided into two sections by an interior brick wall running along the building’s east-west centerline. The roof deck is sloped to drain to the west, and falls from about three feet below the top of the parapet on the east to six feet from wall top on the west. Stormwater runoff drains from the roof through two scuppers and downspouts located along the west wall. The drainage downspouts join at the northwest corner of the building and flow underground to the city sewer.

The roof deck is covered with a tar and felt built-up roof membrane. The roof support structure has not been exposed, but is assumed to be similar to lower levels of the building. This system is wood decking over wooded joists that span from bearing walls to the interior column lines. For the purpose of this concept design, the roof system design is assumed to carry a 40 psf live load in addition to the dead load. The actual capacity of the structure must be verified when structural members are exposed, measured, and analyzed for strength.

The Garden Concept Design

The roof garden is planned to occupy the north part of the roof, with a photovoltaic array established on the south roof. The proposed rooftop garden has a different roof treatment in each of two sections. The northern section contains a pedestrian deck with planters and a trellis. The deck is built on multiple levels connected by stairs and ramps. A viewing deck is located on the north and east sides, providing a view of Downtown and Page 43 THE OMAHA GREEN BUILDING INITIATIVE

the Missouri River valley. The deck‘s south side, adjacent to the interior wall, is shaded by an overhead trellis. The deck will be built on a level plane and will be about four feet above the roof deck on the west side. The edge of the deck will include a guard rail, and will be set back from the outside wall by a buffer four feet in width.

Raised planter boxes are planned between the two deck areas over a supporting column line. The planters will be filled with lightweight soil mixtures to minimize the additional roof load. The planters will contain a variety of plant types including herbs and veg- etables. Vines could be planted to extend over the trellis.

The decking and planters will be constructed with plastic lumber made from recycled plastic. The southern roof section will be covered with a “Sopranature” roof covering system, which includes a lightweight soil layer covered by plants and grasses that have been selected for the environment.

Page 44 ~~~~ ~~ ~ THE OMAHA GREEN BUILDING INITIATIVE

Access

Currently, roof access is provided by an outside vertical ladder that extends from the fourth floor fire escape to the roof. Future access will be provided by an extension of the elevator and stairway to the roof level. Access points will be located along the south side of the interior wall. Part of the wall will be removed to provide an opening for a walk- way.

Water Storage System and Beneficial Use

Based on an approximate roof area of 5,200 square feet and average annual precipitation of 27.5 inches, nearly 88,OOO gallons of water will fall directly on the roof during a year. Currently, all roof stormwater flows to the storm sewer. The concept design proposes capturing as much water as possible for on-site beneficial use. Potential uses include imgation of planters and the Sopranature roof and for non-potable domestic use, such as gray water for toilet stools. Water should be stored at the highest possible elevation to save on pumping costs. Because stored water is heavy, the storage tanks should be located near a bearing wall or over the column lines. The planter irrigation water will be stored in containers located over the column line under the planter boxes. Final design will involve determining the amount of storage needed to provide for anticipated water usage between rainfall events.

Connections to the Surrounding Community

The Pullman Hotel site will be connected to the local community by a bicycle route linking it to the Back to the River project (BTTR), a comprehensive development effort to establish a recreational trail and greenway system along the Missouri River corridor. According to BTTR, a multi-use trail will be developed along the Missouri River’s west bank near Downtown Omaha. A bicycle route or path will connect the river trail to the Gene Leahy Mall, and extend west along Farnam Street to Street. The route will continue south along loth Street past the Pullman Hotel to the Henry Doorly Zoo. A branch of this trail will extend east on Walnut Street to 6&Street, south to Martha, and east to reconnect with the BTTR Trail.

The proposed loth Street trolley route also passes by the Pullman Hotel. Preliminary plans call for a station at loth and Pacific, which may be developed in conjunction with the Upper Terrace Park. -

Thus, the Pullman is located advantageously within the emerging riverfront corridor and can be a contributor to a linked system of attractions and urban features. Its character as a contributor to the growing urban district will ultimately increase its value to residents.

Page 45 THE OMAHA GREEN BUILDING INITIATIVE

Chapter Six PROJECT COST ESTIMATES

THE PREVIOUS SECTIONS HAVE CONSIDERED KEY DETERMINANTS OF GREEN BUILDING DESIGN for the Pullman Hotel. The next two sections consider the feasibility and implementation of the project. This discussion summarizes probable project cost and considers the financial impact of using green materials and building techniques.

Table 6-1 summarizes cost estimates for the building developed by John Luce Company, general contractors. Based on the conceptual design, material specifications, design features, and recommended mechanical systems, the building rehabilitation cost is calculated at $1,628,432, or about $80 per square foot excluding the basement or $67 per square foot including the basement. This is somewhat above the cost of other comparable adaptive reuse projects in the Old Market district. However, in developing this estimate, the contractor utilized a "guaranteed maximum price" (GMP) technique. GMP estimates generally are reduced as detailed design of a project proceeds. The contractor estimates that final building rehabilitation costs may be 15% below this estimate. Based on this

Table 6-1 Green Building Estimate Report

Item Description cost

1000.00 General Conditions $147,425 2000.00 Sitew ork 159,000 3000.00 Concrete 22,000 4oO0.00 Masonry 5,000 6000.00 Woods and Plastics 69,463 7000.00 Thermal and Moisture 36,500 8000.00 Doors and Windows 146,600 9000.00 Finishes 3 15,260 1oooO.00 Specialties 1,680 14OOO.00 Conveying Systems 94,000 15000.00 Mechanical 325,442 16OOO.00 Electrical 149,997 Taxes 8,026 Profit 148,039

Total Rehabilitation Cost 1,628,432 Page 46 THE OMAHA GREEN BUILDING INITIATIVE opinion, a probable rehabilitation cost of $1,384,000 is used in the next chapter to test project feasibility.

Many green materials identified in the project have insignificant cost implications. Table 6-2 identifies those items which have significant cost implications. It is important to note that this table only includes items with significant cost implications. Other “green” materials identified in this report are comparable in cost to conventional selections.

Table 6-2 Cost Comparisons of Green and Conventional Materials

Material Unit Cost for Comparable Green Conv Comments Materials cost Cost

Sheetrock Unit: 4’s8’ sheet $165,432 $148,574 Green material specification Wallboard Green: is for recycled material $6.50 for 112” , (kraft paper is 25%recycled) $7.46 for 518”. fabricated in Fort Dodge, Conventional: Iowa for reduced transporta- $5.69 for 112” tion cost. $6.87 for 518”

Insulation Green: 34,000 18,360 Green material does not use $1.00/SF for aircrete blown insula- virgin fiber pulp and tion; Conventional: $0.54 for batt provides safer insulation. insulation

Doors Green: 6,000 5,640 Recycled material. Steel door and frame: $300 for 16 gauge. Conventional: Hardboard door and wood frame: $282

Mechanical Green: 180,000 100,OOO Heat pump provides system Fan coil units.. efficient space conditioning Conventional: and installation rebate. Forced air units. However, fan-coil units generally have lower impact on environmental emissions.

Windows Green: Advanced double-glazed 134,100 108,000 Improved insulation offers windows with interior screens. significant energy savings Conventional: Clear double-hung by increasing integrity of windows with interior screens. envelope.

Total 519,532 380,574 Page 47 THE OMAHA GREEN BUILDING INITIATIVE

This analysis indicates that the added cost of “green” features in the Pullman Building is about $139,000 more than the cost of conventional materials, or about 10% of overall project cost. If air-to-air heat pump units are used in place of fan coils, the initial differential falls to about $llO,OOO or 8%of total project cost. An analysis completed in April, 1999 by ENSAR Group for the building projects energy savings ranging from $11,700 to $16,700 annually, with a simple payback period ranging from seven to ten years. This indicates full amortization of these improvements at market interest rates over a 15 to 20- year period.

Other Project Components

The sitework and rooftop garden components of the Green Building project also involve significant costs. Estimated cost of these site improvements is summarized in Table 6-3 and compared to the cost of conventional parking lot construction. The 89 stall parking lot included in the cost estimate exceeds the requirements of the Pullman Hotel alone. After adjusting for the cost of conventional parking lot requirement, added cost for construction of green buildingleco-park concepts is estimated at $230,871.

Table 6-3 Sitework Costs Sitework Component cost

Rooftop Garden $69,863 Parking Lot 191,758 Upper Terrace Park and Street Landscape 58,250

Total Sitework Projects 319,871

Conventional Parking Lot Cost (89,ow

Green Project Added Cost 23037 1

Page 48

THE OMAHA GREEN BUILDING INITIATIVE

Chapter Seven PROJECT FXASIBILITY AND FINANCING

THIS SECTION ADDRESSES THE ISSUE OF PROJECT FEASIBILITY AND FINANCING. It considers total project costs and debt servicing capacity based on annual operating expectations. The section concludes by proposing a capital financing program that assembles various funding sources to complete the project.

Project Development Costs

Table 7- 1 below reviews projected project development costs. This calculation ex- cludes site development cost related to the green building concept, but which are difficult to amortize through conventional means. These include added costs related to the rooftop garden, “green” parking lot development, and Eco Park construction.

Table 7-1 Estimated Project Development Cost Cost Items cost Assumptions

Acquisition $200,000 Based on 15% savings from current GMP Building Rehabilitation 1,384,000 Parking 30,000 30 conventional stalls at $l,OOO per stall Landscaping 15,000 Contingency 71,450 5% of cost estimate

Hard Cost Subtotal 1,500,450

Interim Taxes 11,Ooo Insurance 1,500 Design Fees 109,3368 7% of construction cost Development Management 20,000 Interim Interest 81,760 7% of supportable mortgage Rent Up Fee 3,150 Debt Financing Fee 23,200 JJ%d JJ%d 2,500 AccountinglAuditing 1,500 Appraisals 2,500 Title Insurance 1,500 Recordation/Misc Closing Costs 600

Soft Cost Subtotal $258,578

Total Development Cost 1,7_59,028

Page 49 THE OMAHA GREEN BUILDING INITIATIVE

Three major components make up total project cost:

Acquisition, estimated at $200,000, or approximately $10 per square foot. Hard costs, for construction and contingencies. Soft costs, including professional fees, financing costs and fees, development fees, and other similar costs.

Based on this analysis, total project cost is estimated at approximately $1.76 miliion.

Operating Statement

Table 7-2 presents an annual operating statement for the Pullman Hotel project. This calculation summarizes the financial performance of the project and calculates the amount available for debt service. This statement assumes that:

Average monthly residential rents for apartments in the Pullman development are $0.90 per square foot. This indicates a rental range between $465 and $657.

Office and commercial space at street level leases for an average of $10 per square foot triple net.

Garage parking revenues are calculated at $50 per month. Surface parking is provided at no cost to residents.

Project Financing

Table 7-3 identifies sources of funds and financing gaps for two scenarios - the rental scenario described above and a condominium scenario, based on sales of units at an average price of $100 per square foot. Financing gaps under the two scenarios are similar. Although sales of condominium units generates somewhat more revenue than a supportable first mortgage, the availability of historic tax credits partially compensates for this difference. In addition, a rental project has a far better chance of absorption in the downtown marketplace than a small unit condominium project.

Of the calculated gap, $1 13,000 is accounted for by use of green building materials and technologies, about 8% of total construction cost. Grant sources specifically designated for “green” projects, such as the Nebraska Environmental Trust, may be tapped for this sum and for special sitework related to the Eco-Park and parking lot. Funding these items would require about $344,000 in supplementary grant funds. An additional

Page 50 Table 7-2 Projected Annual Operating Statement

Item Number Area Rent/SF Rent/ Annualized Assumptions of Units (SF) Unit/ Total Month Revenues Unit A 3 730 $0.90 $657 23,652 Unit B 3 570 $0.90 513 18,468 unit c 3 572 $0.90 515 18,533 Unit D 3 538 $0.90 484 17,431 Unit E 3 517 $0.90 465 16,751 Unit F 3 577 $0.90 519 18,695 Unit G 3 606 $0.90 545 19,934

Office 2,334 $10.00 23340 Commercial 945 $10.00 9,450 Parking 6 50 3,600

Subtotal 165,954

5% Vacancy

Effective Gross 157,656 Revenue ExDenses Red Estate Taxes 32,198 Insurance 2,862 $0.15/GSF Common Utilities 3,113 $0.75/GSF Management 6,306 4% of rentals Maintenance 7,560 $30/unit Replacement 7,017 0.5% of construction 4,000 Operations Subtotal 63,055

Net Operating 94,601 Income

Cash Flow 12,613 8%of gross revenues Expectations ~

Available for 81,989 Debt Service

Page 51 THE OMAHA GREEN BUILDING INITIATIVE

$152,000 financing gap remains in the rental scenario. Community Development Block -- Grant (CDBG) funds have the potential to fill this gap under the statutory intent of pre- venting or eliminating slums and blight. Additional construction cost savings or revenues ~ could also realistically close the financing gap. ~

Table 7-3 Sources of Funds and Financing Gap Funding Source Funding Assumptions

ENTAL SCENARIO

Supportable Mortgage $1,026,963 7%, 30-year amortization TIF loan 150,000 Based on $1.3 million incremental value Tax Credit Equity 3 16,800 20% of eligible basis

Total Funds from Identified 1,493,763 Sources

Gap (excluding Eco-Park sitework) 265,265

CONDOMINIUM SCENARIO

Unit Sales 1,233,000 $100/SF TIF loan 150,000 Supportable Debt for Street Level $219,261 7% 30-year amortization, 25% vacancy discount Total Funds from Identified 1,602,261 Sources

Gap (excluding Eco-Park sitework) 156,767

Page 52 THE OMAHA GREEN BUILDING INITIATIVE

Chapter Eight APPLYING GREEN BUILDING PRINCIPLES TO OTHER PROJECTS

THIS REPORT DOCUMENTS THE PROCESS OF APPLYING GREEN BUILD- ING AND LANDSCAPE PRINCIPLES TO THE PULLMAN HOTEL, a relatively typical older building in Downtown Omaha. In general, we found that:

1. Basic common sense building investments, including improving the thermal performance of the building envelope through insulation and efficient windows, maximizing ventilation, and using daylight effectively have significant benefits for the economical operation of buildings.

2. Thoughtful material selection can decrease overall energy costs and, in many cases, improve the health and productivity of building users.

3. Rehabilitation design according to “green” principles accounts for a relatively small increment of overall project costs. Moreover, the operating savings obtained by applying these principles amortizes the modest added cost over the life of a typical mortgage.

4. Careful building planning, based on the operating characteristics of various uses, can also improve the energy performance of a project. Thus, locating uses such as offices, with high daytime heat generation and cooling demands, on the north side of a mixed use building and placing uses with higher evening and night intensity (such as resi- dences and restaurants) on the south side, minimizes overall energy use.

5. To the greatest degree possible, green principles should extend beyond the walls of a building and be incorporated into the project’s site plan. These principles include minimizing urban runoff and reducing solar heat gain from expanses of paving by landscaping and shading.

6. A variety of other technologies exist that require further testing in specific applications to demonstrate their feasibility. Some of these technologies include expanded use of photovoltaics and ground-source heat pumps. At present, incorporating these elements into projects may require supplemental demonstration grant funding.

The adaptive reuse of historic buildings in Omaha in general and Downtown Omaha in particular has been a major engine for revitalization of the central city. From pioneer- ing projects such as the Howard and Windsor Hotels in the Old Market and Union Plaza, the Regis, and Orpheum Tower in the central Downtown district, downtown residential reuse has become a major trend in housing development in the city. This

Page 53 THE OMAHA GREEN BUILDING INITIATIVE

trend will continue in the future, as the growth of the Old Market, the Back to the River program, rapid growth in downtown, and the proposed development of a new convention center and arena make Omaha’s central business district an increasingly popular living and working environment. We hope that the lessons of the Pullman project can be used effectively by other similar projects.

To this end, the checklist provided on the following pages presents criteria that can be used by developers of rehabilitation projects to evaluate their project’s design, materials choice, site development, and other features. The checklist provides questions that designers and developers should consider as they pursue specific projects and has been adapted from the excellent Pollution Prevention Reference Guidefor Montana Residen- tial Construction (Montana Pollution Prevention Program and Montana State University Extension Service, October, 1998). While not all of these items will apply to each project, the checklist provides a summary of important questions to consider.

Ultimately, the value of the Green Building and Eco Park effort will be measured not just by the eventual development of the Pullman Hotel according to green principles, but also its influence on subsequent projects.

Page 54 THE OMAHA GREEN BUILDING INITIATIVE

Site Planning and Development

Does the site plan minimize earthwork?

Are parking areas shaded or broken up by landscaping?

Is off-site urban runoff minimized by the site design?

Does the site design provide amenities for users or for passersby? Planning

Does the plan make most productive use of interior space>?

Have you considered mixing uses in the building?

Are uses with high daytime use and heat gain generally located on the north side of a mixed use building?

Are uses with lower daytime cooling requirements located on the south side of the building?

Is the project designed to make maximum use of existing materials, reducing waste during construction?

Has the construction process been designed to manage construction-generated waste? Framing and Construction Techniques

Has engineered or composite lumber been considered for beams, joists, headers, and other structural components?

Have steel studs and joists been considered instead of wood? Insulation

Will the exterior walls and roof be adequately insulated?

Will exterior doors have proper insulation and infiltration seals?

Has an insulated metal door with weather stripping been considered for outside entrances?

Has fiberboard insulation made from recycled paper been considered for areas beneath carpet or under roofing?

Will insulation contain a minimum of 25% recycled content?

Has the use of blown-in cavity insulation been considered? Page 55 THE OMAHA GREEN BUILDING INITIATIVE

Materials e Is wood used from sustainably managed forests? e Does the design primarily incorporate woods from fast-growth forests as opposed to old- growth timber? e Before purchasing new materials such as lumber, doors, windows, and so forth, will sources of recycled materials be researched? e Will the project use materials that are durable and can be recycled in the future? e Has energy-rated, toxic-free natural insulation (such as cotton or cellulose) been considered? Flooring a Will the sub-floor and underlayment be constructed with recycled content materials?

~ e Will oriented strand board (OSB) made from fast growth materials be used for sub- flooring? e Will urea formaldehyde-free sub-floor and underlayment be used? e For carpeted areas, will recycled-content carpet pad and carpeting be used and will it be tacked rather than glued? e Will natural linoleum be used in placed of vinyl flooring? e Has recycled-content ceramic tile been considered for tiled areas? Other Finishes e Will formaldehyde-free particle board be used for inside finishing work and cabinets? e Will water-based urethane and lacquer finishes be used on wood floors and other interior woodwork? e Have recycled-content paints and finishes been considered as an alternative to new finish products ? e Will paints and finishes containing minimal VOCs (volatile organic compounds) or airborne toxics be used?

Page 56 THE OMAHA GREEN BUILDING INITIATIVE

Energy Use: Structural

Will energy efficient lamps and equipment be used during construction?

Have you considered the possible use of photovoltaics as a supplemental energy source?

Will the south gIass area of the project be between 5% and 7%of the total finished floor area?

D Will the structure receive advanced as well as basic sealing? Advanced sealing adds protection to the top and bottom plates, comers and between cavities at penetrations for plumbing, electrical, and ventilation systems)

# Will solar-rated/energy efficient double-paned or extra glazed windows and doors be installed to reduce heat loss and minimize external noise?

D As an alternative, will Low-E windows be considered to increase insulation values? Energy Use: WAC Systems

CI Will a furnace and air conditioning system with high energy efficiency rating be installed? cl Have you considered a balance of both capital costs and energy use in selecting the HVAC system?

D Have you considered the design of the building to maximize natural ventilation?

D If the building has a large floor plate, have you considered the use of ventilation stacks? Appliances and Water Use

D Will energy efficient appliances be used in the project?

# Will water conserving showerheads, faucets, and toilets be installed?

D Will water saving appliances be installed or a list provided to residents? Lighting

D Will windows and skylights be provided to maximize use of daylighting?

D Will the interior use light and heat reflecting materials and surfaces?

CI Will the project incorporate energy efficient lighting and control systems?

D Have you considered the use of light shelves and other reflective devices?

Page 57

SUSTAINABILITY REPORT

ENSAR Group, Inc. 2305 Broadway Boulder, CO 80304

June 25,1998 Project #9867 THE PULLMAN _I Omaha, Nebraska

. Table of Contents

Executive Summary ...... 2

Baseline Data...... Base Building Description ...... Utility Rates ...... Climate Data ...... 6 Energy Use and Operating Cost ......

Energy Efficiency Oppomnities ...... Individual Strategies ...... 8 Ranking of Energy Efficient Strategies ...... 8 Energy Efficient Strategies of the Building Envelope and Lighang Systems ...... 10 Glazing ...... 10 Daylighting ...... 11 Building insulation ...... 12 Passive Ventilation and Cooling ...... 12 Passive Heating ...... 12 Electric Lighting ...... 12 WAC Systems ...... 12 Analysis Results ...... 13 Green Building Evaluation ...... 21 AttachmentdG1ossax-y...... 22 USGBC LEED BuildmgTMRating System Criteria Glossary

The Pullnian Omaha. Nebraska Executive Summary

__ The Pullman Hotel is an historic building (Fig. 1) in Omaha. Nebraska, that is planned to be renovated by the Nebraska State Recycling Association, in cooperation the Joslyn Castle Institute. The intent is to with ~ make this a demonstration of green bidding applications. ENSAR Group, Inc. was commissioned to assist in developing green building strategies for the project. ENSAR studies include an analysis of energy efficiency opportunities for the project and an evaluation of environmentally sustainable design opportunities. This Sustainability Report is a summary of the results of ENSAR’s studies. To make recommendations on energy efficiency measures, ENSAR used the Energy-10 analysis program as a basis of comparison. A base case energy profile of the building was established using the architectural drawings and site observations. Assumptions were made for such items as building occupancy, lighting power densities, WAC systems, and other internal loads under the proposed mixed- use of office and apartments. The energy studies concentrated on building envelope measures. Ove Arup & Partners, Califomia, are conducting similar studies for the mechanical systems.

Energy efficiency measures were studied individually, and then in combination. Two levels of measures were compared, one describing moderate measures that would basically up-grade the building to comply with ASHR4E Standard 90.1. The second being advanced measures that will provide a superior performance. The advanced measures represent readily available applications, but the capital costs for these measures were not part of these studies.

Fig. 1 The Pullman Hotel at an early age. This front side is facing west

The Pullman Omaha, Nebraska The annual energy use for the base case has a poor performance of 127.8 kBtdsquare foot-year. The moderate measures are a 70.3 kBtu/square foot-year. The advanced case is reduced to 59.7 Wfoot- year. The annual cost savings are about $1 1,700 the moderate case and $16,700 for the advanced case over the base case. The key strategies used to achieve these values are indicated in Table 1.

Table 1 Key Energy Efficiency Strate ies ~ ~__ Component Base Moderate Advanced Wall Construction U-0.24 (R-4.2) U-0.063 (R-15.9) U-0.044 (R-22.5) Roof Construction u-0.22 (R-4.5) U-0.053 (R-19.0) U-0.026 (R-38.0) Windows Overall U U-0.96 U-0.29 U-0.18 Glazing U u-1.11 U-0.26 u-0.12 Shading Coefficient sc 1.0 SC 0.65 SCO.52 Daylight Transmittance T~is90% TviS 75% TVis 62% South Glazing Area (YOof south wall) 7% 14% 14% Daylighting Controls None Continuous Dimming Continuous Dimming at at Perimeter Perimeter 1.78 Wisf 1.33 Wisf 1.07 Wisf 0.5 Wisf 0.5 Wisf 0.3 Wlsf 80% 80% 80% 8.1 8.1 13.0

The building was evaluated for opportunities responding to environmental concems under a scenario of fairly extensive renovation. The LEED (Leadership in Energy and Environmental Design) Green Building Rating System Criteria was used as an evaluation tool. The LEED system was developed by the US.Green Building Council and is intended to be a dejnitive standard for what constitutes a “green building. ” It is a point system that results in four different categories of a green buildmg, once reaching a minimum level of 22 points. The LEED system centers around energy efficiency, minimization of waste, wise use of natural resources, healthy environments and pollution prevention.

Basically, the renovation of the Pullman offers many opportunities to be a green building showcase. It could achieve 35 to 41 points out of 44 possible points (plus 4 bonus points) in the LEED system. The design team should be directed to achieve a selected level of points and give the team the opportunity to evaluate implementation costs and select the most appropriate strategies within the project budget.

The Pullman 3 Omaha, hlebraska Baseline Data

This project is for the renovation of The Pullman, a historic building in Omaha, Nebraska. A reference building energy profile for the project was established as a basis of comparison for a variety of energy efficiency strategies. The building envelope conditions were defined as they exist for a baseline (Fig. 2). The building is a 4 story, uninsulated masonry building, plus basement. Each floor has about 5,300 square feet, or 21,168 total. The basement opens up to the east or rear of the building at grade.

The building is elongated in a north-south direction (Fig. 3), with most of the current window glazing on the east (Fig. 4) and west. The front side of the building is Edcing west. The south wall has the least glazing. The windows are clear single glass. The gross window area is about 1,900 square feet of the 15,800 square feet of wall area (about 12%).

The building, known as the Pullman, was a hotel, and is currently an apartment building with a restauranthar at the first floor. The reference building was described with an energy load profile typical for office and apartment uses. The electrical and mechanical systems for the reference building assume probable lighting loads, plug loads, and WAC systems that meet standard practice if the building were to be renovated without an emphasis on energy efficiency. Table 2 is a summary of some of the key information used in the baseline analysis.

The Pullman 4 Omaha, Nebraska Fig. 2 The front (west) elevation of The Pullman as it exists in 1998

ra a 0 0

m 0 0 0 0

NORTH

:ig. 3 Typical floor plan of The Pullman Fig.4 East (rear) elevation of The Pullman

The PuIlnian 5 Omaha, Nebraska Utility Rates

The energy operating cost savings of each EEM is estimated within the context of the cost of powering the baseline building.

Electric Rates

Average $O.O59kWh plus $5.00kW

Gas Rates %OSO/therm

Climate Data

Location: Omaha Nebraska

I Heating Degree Days (65') I 6413 I

41 I Latitude I Lon 'tude Elevation ASHRAE Winter Design Tem erature (99%) ASHRAE Summer Design 94°F Temperature (1 %) Mean Coincident Wet-Bulb 1 76°F Temerature LI I I Annual Cleamess Index 0.53 General Summer Conditions Hot/Humid General Winter Conditions Cold

-3 North 8 East 1500 C .--0 am am 1000 -z r_ c 2 500 -\

0 JFMAMJJASOND Fig.5 Solar Radation

The Pullman 6 Omaha, A'ebraska Energy Use and Operating Cost

The energy use and operating costs for the base case building and subsequent comparisons of energy efficiency measures were predicted using an energy analysis program, Energy-1 0, that simulates hourly energy flows on an annual basis. Energy-10 is a new analysis program that has a simplified approach to incorporating complex information. It is an appropriate tool for analysis on a relative basis for a project of this nature at this point in the design process.

The initial analysis shows that the total energy use is about 127.8 lcl3tdsf-yr at a cost of about $1.34 per sf-year. Figures 6 and 7 illustrate a percentage breakout of annual energy use and cost.

Other 12.2%

Fig. 6 Energy End Use Breakout as a percentage of annual energy use

Other

18.6%

Fig. 7 Energy End Use Breakout as a percentage of annual energy cost

The Pullman 7 Omaha, Nebraska Energy Efficiency Opportunities

Individual Strategies

As with any energy analysis, it is difficult to consider all items that affect performance, and there are too many variables to predict exact operating costs. The most useful information for this study is the difference between the base case and the specific measure or measures being studied.

These measures are considered individually first in the initial study, and then collectively, since the dynamics of energy performance will change when assessed collectively versus individually. A holistic approach of combining the strategies is typically the most effective.

The first step in the evaluation process was to rank selective individual energy efficiency strategies as a sensitivity analysis. This study focused on building insulation, window glazing, daylighting, thermal mass, passive solar heating, and energy efficient lights. Each individual strategy was applied to the baseline or reference building to observe the single effects.

Insulating the building came in as the first priority for the building in regards to energy use and operating cost. Window glazing improvements, daylighting, and energy efficient lights came in 2nd ,3rd, and 4* in energy use and cost, but varied as to order due to different costs for electricity and fbel. Passive solar heating (which basically means adding windows to the south wall) actually shows a negative savings. This is because during the winter the solar heat gain is lost due to poor insulation and windows in the baseline and it provided too much summer heat gain. Passive solar heating looks much better in the combined runs after the other measures are included.

The following energy efficiency strategies were used for the ranking in Figures 8, 9 and 10:

Insulation Walls U-0.063 (R-15.9) Roof U-0.053 (R- 19.0) Glazing Clear double low-e U-0.29 (window), U-0.26 (glazing), SC 0.65, Tvis 75% Daylighting Continuous dimming controls with 30 FC ambient plus task lights Thermal Mass Using the thermal mass of the existing masonry walls by insulating the exterior walls (values are given showing basically the difference of adding the same insulation to the exterior as to the interior) Passive Solar Heating Benefit by a total of 19% glazing in the south wall (this is too much and is most appropriately sized at about 14% when other measures are taken)

The Pullman 8 Omaha, Nebraska Green Buildinn-Eco Park / Base 2 I

Fig. 8 Passive Ranking of Solar Heating m-886 Energy Cost Savings -2000 0 2000 4000 6000 BaseCase = S 28370 Annual Energy Cost Saungs, $

-814

Fig. 9 Ranking of Energy Use Savings -250 0 250 500 750 1000 BaseCase = 2706 MBtu. Annual Energy Savings, MBtu

114.3

-118.3

i- i- 122.2

-1 -1 129.4 Fig. 10 Rankingof Peak Electric Demand 0 50 100 Peak Electric Demand, Irw

The Pullman 9 Omaha, Nebraska Energy Efficiency Strategies of the Building Envelope and Lighting Systems

The architectural systems and components are used as a means of reducing loads and in some cases

eliminate mechanical systems. The building envelope is a selective pathway to achieve efficient and cost- ~ effective solutions especially related to glazing, daylighting, and insulation. Passive systems for ventilating, cooling, and heating use the architecture to relieve and eliminate mechanical systems to do the same.

These strategies are described at two levels. First the Moderate level represents rather standard practice and generally complies with ASHRAE Standard 90.1. The second level represents Advanced practice techniques to achieve low energy buildings.

Glazing

The existing windows are primarily single pane glass in wood frames. To up-grade to the moderate measures, clear double windows with low-e coatings are proposed. The south wall window area was increased to about 14% of the wall area from the existing area of 7%. The other window areas are as they exist today, with about 12% on the north, 11% on the east, and 12% on the west.

The advanced measures include a suspended-coated film within the glazing strategies. This type of glazing will provide a high performance.

Argon or krypton gas fill may be used in the glazing, but it appears not to be necessary.

Another approach to glazing is to rebuild or add to the existing windows. This approach could yield values at both the moderate and advanced levels.

Figures 1 1 and 12 illustrate the variations in glazing characteristics

1.2

G1 G B o.8 0.6 0 $ 0.4 0.2 5 ‘v; .$ 1.2 0 c-. Base Low-e TC88 Shading V Coefficient 11 Heat Transfer Rates of Glazing (COG) S0.8 Fig. Options 8 8 0.6 E Visable s ’i0.4 Transmittance E? 0.2 c-.E 3$0 x Base Low-e TC88

The Pullman Fig. 12 Solar Transmittance Characteristics IO Omaha, Nebraska Daylighting

Daylighting is the effective use of natural light when available to replace electric light. Daylight can reduce energy use and improve the quality of visibility throughout the building. The electric lighting load for the project is about 11%of the building total energy usage, but over 30% of the annual operating costs, including use and demand charges. Daylighting strategies also reduce cooling loads, since there is less heat produced from natural light than from electric light for the same quantm of illumination.

For the Omaha building, the glazing areas were kept the same on the north, east, and west, and increased on the south. Skylights with a glazing area of about 3.8% of the roof area were included in the advanced measures.

Due to the modest size of glazing areas, the potential impact has limitations. The studies to understand the impact of daylighting assumes good visual quality with controls such as venetian blinds (white, horizontal), clear glazing, light colored interiors, and controls on the electric lights to automaticallytum them off when adequate daylight in available.

Figure 13 illustrates the daylight contribution for average days during each month.

Green Buildina-Eco Park / Moderate Measures I

Fig. 13 Lighting Profile for the Base and Moderate Measures The moderate case assumes more efficient electric lighting and continuos dimming controls in response to daylight availability

The Pullman Omaha. Nebraska Building Insulation

The existing building has about 16” of uninsulated masonry walls and an uninsulated flat roof. Studies conducted included increasing the thermal resistance values from about R-4 of the existing to R-15 for the moderate case and R-22 for the advanced case. This could be achieved by “furring out” an interior insulated cavity of 3 %” or 5 %” respectively. It could also be done by an exterior insulated finish system (EFS). The thermal mass of the exterior wall was considered and does provide a benefit if it is insulated on the outside of the building. Due to historic preservation goals, it is unlikely that exterior insulation is possible on the front side and maybe not desirable aesthetically on any elevation. Thermal mass is illustrated in the ranking studies.

Passive Ventilation and Cooling

Natural ventilation will likely provide much of the ventilating and cooling needs. However, Energy-10 does not currently have a feature to allow for an accurate study of this. Some modifications in the cooling system assumptions were made to get an order of magnitude difference for the use of natural ventilation in the advanced measures.

Awnings or shades should be used on the south and west if possible.

Passive Heating

In order to achieve some winter-time solar heat gains, we propose to increase the south window area from about 7% to 14% of the wall. This will enable winter solar heat gains and year around daylighting without much penalty on the cooling loads. Much more than this amount will likely result in overheating, depending upon glazing strategy and/or window treatments (1.e. awnings, shades).

Electric Lighting

Good quality electric lighting is assumed in the analysis. The base lighting power density is 1.78 Wa#s/square foat. The moderate case is at 1.33 Watts/square foot and the advanced case assumes 1.07 Watts/square foot. Occupancy sensors and daylighting controls should be considered, especially in office spaces.

WACSystems

To study the envelope measures, little changes were made in the WAC system efficiencies. The heating system efficiency was kept at 80% for all cases. The cooling system had an EER of 8.1 in the base and moderate cases, and 13.0 in the advanced case. Since Ove Arup & Partners, California, mechanical engineers are involved with the project their recommendations are being supported by the ENSAR Team.

The Pullman 12 Omaha, Nebraska Analysis Results

The energy efficiency strategies were further evaluated individually and then combined in moderate and advanced cases. The moderate case basically complies with ASHRAE Standard 90.1. The advanced case uses higher performance values for many of the strategies, but all are commercially available products and techniques. Table 3 illustrates the key differences in energy efficiency strategies. The results are indicated in Figures 14-26.

The moderate case drops the annual energy use from 127.8 kBtdsquare foot to 70.3 kBtu/square foot. The annual energy cost goes from $1.34 to $0179. The advanced case drops the energy use to 59.7 kBtdsquare foot and the cost to $0.55.

This study identifies groupings of strategies to achieve energy savings of 45% to 53%. More savings can be realized in the mechanical systems. To select the most appropriate combination of strategies based on cost (implementation, savings and life cycle), the capital cost for implementation needs to be established. This process needs to include cost for higher efficiency and credits for items like smaller WAC equipment.

Component Base Moderate Advanced Wall Construction U-0.24 (R-4.2) U-0.063 (R-15.9) U-0.044 (R-22.5) Roof Construction u-0.22 (R-4.5) U-0.053(R-19.0) U-0.026 (R-38.0) Windows Overall U U-0.96 U-0.29 u-0.18 Glazing U u-1.11 U-0.26 u-0.12 Shading Coefficient sc 1.0 SC 0.65 SC0.52 Daylight Transmittance Tvis 90% Tvis 75% Tvis 62% . South-Glazing Area (%of south wall) 7% 14% 14% Daylighting Controls None Continuous Dimming at Continuous Dimming at Perimeter Perimeter Lighting 1.78 Wlsf 1.33 Wlsf 1.07 Wlsf Plug Loads 0.5 Wlsf 0.5 Wlsf 0.3 Wlsf WACHeating Efficiency 80% 80% 80% Cooling System EER 8.1 8.1 13.0

The Pullman 13 Omaha, Nebraska Fig. 14 Annual Energy Use ~tu/sf-vear)for base and MODERATE measures

Fig. 15 Annual Energv Cost Breakdown for base and MODERATE measures. He total mer@cost for the base is $1.34/sf-year and $0.79/sf- The Pullman year for the moderate level 14 Omaha, Nebraska Fig. 16 Daily Energv Pmfiia during Peak Choling period for Base and MODERATE measures

Fig. 17 Monthly Average Energy prolles for Base and MODERATE measuns

The Puffman Omaha, Nebrash Fig. 18 PeakEleCtiic Demands (kw)for Base and MODERATE measures

Fig. 19 Monthly Energy Use Breakout for Base and MODERATE measufes

The Pullman I6 Omaha, Nebraska Fig. 20 Annual Energy Use (kBldd-year)for the base and ADVANCED measures

Fig. 21 Annu;iI Energy Cost Breakrdown for be and ADVANCED measures. The total energy cost for the base is $1.34/sf-yearand $Oo.55/sf-yearfor the advanced level.

me Pullman Omaha, Nebraska Fig. 22 Daily Energy Profiles during Peak Cooling Period for Base and ADVANCED measures

Fig. 23 Monthly Average Energy profiles for Base and ADVANCED The Pu IImn 18 Omaha, Nebraska .-

Fig 24 Peak Electric Demands (kwfor Base and ADVANCED measms

Fig. 25 Monthly Energy Use Breakout for Base and ADVANCED measures

7he Psrllman 19 Omaha, Ncbrnska 4000 3500 3000 2500 2000 1500 1000 500 0 Base Moderate

Fig. 26 Air Pollution Emissions from Natural Gas and Electric Power Plants for the Base, Moderate and Advanced measures for the Pullman. The emissions include CG,Sa, and NOX. Over a twenty year period the emissions savings for the Moderate level is 1,379 tons and 2,278 tons for the Advanced level.

The Pullman 20 Omaha, Nebraska Green Building Evaluation

In order to define the opportunities for the renovation of The Pullman to be a green building showcase, the LEED (Leadership in Energy and Environmental Design) Green Building Rating System was used. The LEED system was developed by the U.S.Green Building Council as a method for defining what constitutes a “green building.”

A total of 44 Credits, plus 4 Bonus Credits are available under the LEED Building Rating System with four categories:

1. LEED Building Platinum for buildings that eam 81% (36) or more of the available credits 2. LEED Building Gold for buildings that eam 71-80% (3 1-35) of the available credits 3. LEED Building Silver for buildings that eam 6 1-70% (27-30) of the available credits 4. LEED Building Bronze for buildings that eam 50-60% (22-26) of the available credits The opportunities for the Pullman building are extensive. Many of the components can be met at a low to moderate implementation cost. However, some may be quite costly. The design team should be given direction to evaluate the performance and cost of individual measures and “whole building” renovation techniques with a selected target of LEED points (22 being minimum). Compensation to the design team could be based upon the level that is achieved.

Table 6 indicates the possible credits that The Pullman building renovation could achieve. The budget implication and cost effectiveness will need to be assessed in order to make the final selection of strategies. The attached USGBC LEED Building Rating System Criteria includes more detailed description of these items.

Water Quality I 1-2 TOTAL I 35-41

The Pullman 21 Omaha, Nebraska Attachments

USGBC LEED BuildingTMRating System Criteria Glossary

The Pullman 22 Omaha, Nebraska USGBC LEED BuildingTMRating System Criteria Breakout of Possible Credits Possible Credits for The Pullman Total Prerequisites 0 Asbestos Avoidance OT Management J If architect of record certifies no asbestos 0 Building Commissioning J If building is commissioned according to the Bonneville Power Administration’s Building Commissioning Guidelines-Second Edition 0 Elimination of CFC’s J If CFC and halon fire suppression systems are not permitted

0 Energy Efficiency J Existing building is far from complying with ASHRAE Standard 90.1. Upgrades for the building envelope and electrical systems to comply with ASHRAE Standard 90.1 are described in the moderate case in this packet. The advanced case exceeds this requirement by 15% and could exceed it by more than 20% ifthe WAC system were made more efficient. Indoor Air Quality J Assuming compliance with ASHRAE 62-1989 IAQ 0 SmokingBan J Assuming The Pullman Hotel will prohibit smoking anywhere in the building. 0 Storage & Collection of Occupant Recyclables J 0 Thermal Comfort J Presumably, this building will meet ASHRAE 55-1992. However, natural ventilation may cause a problem. Water Conservation J Probably complies Water Quality - Lead J Probably complies

Through renovation, the building should comply with all prerequisites.

The Pullman Omaha. Nebraska Possible Credits Total For The Pullman Building Materials (7 Credits) LOWVOC 2 a) Require the specificationsto limit VOC content in adhesives and comply with South Coast Rule #1168 b) Require the specifications to limit VOC content in sealants and comply with Regulation 8 and Rule 51 of the Bay Area Air Resources Board c) Require the specifications to limit the VOC content in paints and coatings and comply with New Jersey state department of Environmental Protection, Title 7, Chapter 27, Subchapter 23 Local Materials 1 Specify at least 20% of building material as calculated by materid cost to be manufactured within 300 miles of building site. Resource Reuse 1 Specify salvaged or refiubished materials for 5% of total building materials as calculated by total materials cost. Advanced Resource Reuse 0- 1 This may be achievable by using components like reused wood for the furred out walls, etc. To make a credit here, specify at least 10% of total building materials as calculated by total materials cost. Recycled Content 2 specify a minimum of 50% of materials as measured by t&l building materials cost that contain at least 20% post- consumer recycled content OR a minimum of 40% post-industrial recycled content.

Subtotal for Building Materials 6-7

Construction Waste Management (2 Credits) Management Plan 1 If a construction and demolition waste management plan is developed and implemented. Advanced Management Plan 1 If the resources are available in Omaha, it is recommended that additional recycling measures be implemented.

Subtotal for Construction Waste Management

The Pullman Omaha, Nebraska Possible Credits Total For The Pullman Energy Efficiency (10 Credits) EPA Green LightsKalifomia Title 24 2 Compliance has not been verified but it’s possible and we suggest at least the following for a level 2 credit. EPA Energy Star Bldg. ProgrdASHRAEOES 90.1 2 by more than 20% Not originally, but could comply under the condition that the advanced case is implemented along with improvementsto the WAC system. Exceed ASHRAEOES 90.1 by 30% Most likely this would be too heroic and costly. Exceed ASHRAEOES 90.1 by 40% No 0 Exceed ASHRAEOES 90.1 by 50% No 0 Natural Ventilation, Heating and Cooling Natural ventilation will provide much of the cooling and ventilating needs. However, in order to meet ASHRAE Standard 55-1992, natural heating and cooling ventilation can only meet comfort requirements for about 6 months. The increase of southern glazing will provide passive heating. Waste-Heat Recovery System

Directly Connected Renewable Energy Systems to supply 10% of load Could be done with photovoltaics on the roof, south window awnings, or on the site. 0 Directly Connected Renewable Energy Systems 0- 1 to supply 20% of load Unlikely, but could be done with a big enough budget. Directly Connected Renewable Energy Systems 0-1 to supply 30% of load Unlikely, but could be done with a big enough budget.

Subtotal for Energy Efficiency 5-8

The Pullman Omaha, Nebraska Possible Credits Total For The Pullman Existing Building Rehabilitation (2 Credits) 100% of the structural shell should be maintained. 2

Subtotal for Existing Building Rehabilitation 2 Indoor Air Quality (3 Credits) Construction IAQ management plan Require the development and implementation of a management plan for the construction process. 0 Advanced construction IAQ management plan Require a qualified advanced construction management plan. 0 Permanent air monitoring system Require a permanent air monitoring system for COYC02, TVOCs, and particulates.

Subtotal for Indoor Air Quality 3

LandscapingDZxterior Design (3 Credits) Erosion Control This specification should not be a problem since The Pullman is an existing building and the site already developed. Reduced heat islands 0 Adjacent parking lot made of light-colored aggregate. Use light colored roofing. It is recommended that one tree be planted for every 1000 sf of impermeable surface on the site

Subtotal for LandscapingExterior Design

LEED Certified Designer + I Bonus Credit Yes, however, the LEED certification system is not in place yet. Assuming that it is by the time The Pullman is designed, certification should be required.

Subtotal for using a Certified LEED Designer 1

The Pullman Omaha, Nebraska Possible Credits Total For The Pullman Occupant Recycling (1 Credit) 0 Occupant recycling Measures 1 At least a 75% diversion rate of the building waste could be met. The recycling should be in the light well in the middle of the east side of the building.

Subtotal for Occupant Recycling 1

Operations and maintenance facilities (2 Credits) 0 Chemical storage areas Require chemical storage and mixing areas. 0 Architectural entryways A system to catch and hold particles is highly recommended and probable for this project.

Subtotal for Operations and Maintenance Facilities 2

Ozone DepletiodCFCs (1 Credit) Elimination of CFC, HCFC an Halon use in mech. Equip 1 0 Elimination of CFC and HCFC in building materials 1 It could be spelled out asprohibited in specifications.

Subtotal for Ozone DepletiodCFC’s 2

Siting (3 Credits) +I Bonus Credit

0 .The Pullman Hotel will be a rehabilitated building. 1 Reduced Habitat Disturbance 1 Again, The Pullman Hotel will be a rehabilitated building 0 Site Preservation & Restoration 0-1 Should comply with limiting construction disturbance & new surface parking to 50 ft. This credit may not be applicable due to the limited site work. 0 Brownfield development NIA

Subtotal for Siting 2-3

The Pullman Omaha, Nebraska .Possible Credits Total For The Pullman Transportation (3 Credits) + 1 Bonus Credit Altemative transportation facilities 1 Bicycle storage, showers, and changing facilities should be included. Site is adjacent to mass transit stops. Efficient building location 1 Near bus and fixed rail lines Altemative fueling facilities Probably not. However, these types of facilities are becoming more common throughout the country and may present an opportunity in the future.

Subtotal for Transportation 2

Water Conservation (4 Credits) Water conserving fixtures If measures are taken to reduce water use by more than 20% of US Energy Policy Act of 1992. Water recovery system If a gray water system is integrated. Water conserving cooling towers NIA Water efficient landscaping 1 Trees planted to reduce heat islands should be tolerant of climate, soils, and natural water availability only.

Subtotal for Water Conservation 3

Water Quality (2 Credits) + I Bonus Credit Surfice runoff filtration 1 Pretreatment of runoff from surface parking areas should be integrated into the renovation. Surfice runoff reduction Because paving is already in place, a credit cannot be given. Biological waste treatment 0- 1 It is difficult to justify this expense since The Pullman Hotel is already connected to the grid. However, the adjacent property could be made into a demonstration facility.

Subtotal for Water Quality . 1-2 - TOTAL CREDITS FOR THE PULLMAN BUILDING 35-41 (out of 44 available credits)

The Pullman Omaha, Nebraska Glossary

.- Argon - an inert gas used in glazing units to improve the units resistance to heat flow. Btu - British thermal units. A unit used to measure heat. One Btu is about equal to the heat released from one kitchen match. kE3tu is one thousand Btu. MBtu is one million Btu. Chiller Capacity (tons) - The amount of cooling a chiller supplies. One ton of cooling is equal to 12,000 Btu/hr.

Constant Volume Reheat - A constant volume reheat system supplies a constant volume of air to heat or cool a building. The zones within the building can be individually controlled. The supply duct in each zone has a reheat coil.

Cooling Tower - Serves to reduce the temperature (or expel energy) of water used in refrigerant condensers.

Economizer - an WAC measure that uses outside air for cooling whenever possible EEMs - Energy efficiency measures - strategies applied to the base case during energy analysis. Enthalpy - The combination of internal energy and energy related to the pressure and specific volume of a substance. An economizer damper may retum to its minimum opening position when the outside air enthalpy exceeds the return air enthalpy. Such a control strategy may be used rather than temperature.

Envelope - The exterior of the building (i.e. walls, windows, roof) that separates the building from the outside conditions.

WAC- The building's mechanical systems for heating, cooling, and air conditioning.

Krypton - An inert gas used in window units which has better resistance to heat flow than air or argon.

Lighting Power Density -total connected load (W/sf) of ambient electric lighting system.

The Pullman Omaha. Nebraska ...

Low-e - A thin metallic coating placed on glass or thin plastic films. They typically are used to increase the thermal performance (reduce heat transfer). They also affect the shading coefficient and light transmittance.

Luminous efficacy - K, - or Coolness index, is the ratio of visible transmitlance to shading coefficient.

Plug load -total connected office equipment load, not including ambient lighting and WAC systems.

R-value - The inverse of U-value. Measures heat flow through a material(s).

SC - Shading coefficient is an indicator of how well glazing transmits solar heat. The higher the value, the more solar energy is transmitted. It is relative to a single pane of 1/8" clear glass, which is SC=1 .O. (N, S, E, W in tables refer to window orientation of north, south, east, and west.)

SCF - Suspended coated film. A thin, transparent layer of plastic film with a low-e coating applied. This film is then suspended between two layers of glass. This complete glazing unit can be tuned to maximize the balance of thermal performance (U-value), shading coefficient (SC), and daylight transmimce (Tvis).

Tvis - The percentage of visible light transmittance passing through glass. (N, S, E, W in tables refer to window orientation of north, south, east, and west.)

Ucog - The U-value of the center of glass for a window. The framing and edge characteristics affect the ~ total window performance. U-valueh-factor - The rate of heat flowing through a material in Btu/smr/degree F. VAV - Variable Air Volume where the air delivered to the space is adjusted accordmg to need. VSD - Variable speed drive where the speed is adjusted according to need

The Pullman Omaha, Nebraska GREENBUILDING Eco PARK,0- Bui Id ing Mechan icaI Design Report June 1998

Ove Amp & Partners California Green Building/Eco-Park

Contents: Description of existing building Climate Comfort and Natural Ventilation Envelope Photovoltaics and Solar Panels Rainwater Storage and Collection Trombe Walls Natural Ventilation Strategies Mechanical Systems

Appendix - 7 -\ Green Building/Eco-Park

Description of existing buiiding: The existing building has load-bearing brick walls 1% bricks thick with sheetrock finish on the inside. Windows are recessed into the walls and are generally double-hung sash windows. Some of these have been upgraded to insulating glass units, many of the windows in the unoccupied portion of the building are broken. Floors and beams are timber.

The building was designed to be naturally ventilated and daylit and therefore has a narrow plan. The building was originally used as a railway hotel.

There are some window mounted air-conditioning units for summer cooling. Heating is from a boiler in the basement. Cast iron radiators present throughout the building are probably not worth re-using due to the danger of leaks.

\\SUN6UNDMDUALUdOmYlrdoc 1 Green BuildingEco-Park

Climate: The Omaha climate is continental with hot summers, cold winters and short transition seasons. Most of the precipitation fails in the summer months. The sun shines approximately 50% of all possible hours in winter and 75% of all possible hours in summer,

0.4% exceeded 1% exceeded 2% exceeded 95OF dry bulb 92OF dry bulb 89'F dry bulb 75OF coincident wet bulb 75OF coincident wet bulb 73OF coincident wet bulb J

99.6% exceeded 99% exceeded -7'F dry bulb -2OF dry bulb

Jan Feb Mar Apr May Jun Jul Aug- Sep Oct Nov Dec 21OF 27OF 38OF 52OF 63OF 73OF 77OF 75OF 66OF 54OF 39OF 27OF .8' .9" 1.9' 2.8" 4.3" 4.1" 3.8" 3.8" 3.4" 2.1' 1.5" .9"

The total number of heating degree days' is 5968 at a base of 65OF (appropriate for residential) and 2981 at a base of 5O0F (appropriate for office). -. The total number of cooling degree days is 1130 at a base of 65OF and 3618 at 5OOF.

' Degree days am defined as follows: +I- (Base temperature -Actual temperature) x number of days for which this actual temperature occurs. As a reference at base 65°F NYC has 5022 heating degree days, Minneapolis has 8060 and San Francisco has 3238. At base 65°F NYC . has 834 cooling degree days, Minneapolis has 773 and San Francisco 73. (Degree day information from ASHRAE 90.1- igaq

\SUN("DNlOUALVc\O"a.da 2 Green BuildinglEco-Park

Comfort and Natural Ventilation:

Comfort is dependent on a number of factors including air temperature, radiant temperature, .- humidity, air movement, clothing level and activity. More recent research indicates that occupants who have control over their own environment are likely to tolerate larger temperature swings than those without.

For sedentary occupants, with control over their environment, the minimum comfortable air temperature is around 64OF and the maximum temperature is around Bl*F.(From ASHWIE Standard 55) To achieve comfort across this range of temperatures it is important that occupants dress appropriately. From the chart above, the months in which the average temperature falls in this range are May to September. .- d

Radiant temperature is defined as the mean temperature of all the surfaces surrounding a person, weighted by the angle which the surface occupies. Sitting in the sun will lead to a high radiant temperature, as will sitting by a fire. Radiant temperature has the effect of allowing sunbathing on days when the temperature is cool. It may also cause cold discomfort next to the windows of an otherwise warm room on cold days.

Increased air movement can extend the range of comfortable temperatures up to 85OF or so. In , office space increased air movement can cause papers to fly off desks.

Natural ventilation using openable windows is appropriate when the temperature is between 6OoF and 8OoF, depending on the use of the space. In office space it is possible to naturally ventilate at cooler temperatures, down to about 5S0F,provided that occupants are not sitting in a draft If there is a night time ventilation strategy to cool the building down then natural ventilation is viable at higher day time temperatures.

When the outside temperature is very low it is possible to naturally ventilate residential space through trickle openings, preferably located close to the heat emitters. Bathrooms and kitchens should be provided with exhaust fans to prevent the build up of humidity. This is not possible for office space because the occupancy, and therefore the fresh air requirement, is higher.

RECOMMENDATION: A realistic goal for this project is to provide natural ventilation for residential space for the whole year, with air-conditioning provided for peak days only. For office space this target should be reduced to six months, with natural ventilation allowed in other months when outdoor conditions are reasonable. (March, April, May, June, September, October) Green BuildinglEco-Park

Envelope: The building envelope has a significant effect on building energy use, especially in naturally ventilated buildings or buildings with low intemal loads. The envelope may be thought of as a climate moderator; it is used to reduce the effect of the extemal climate on the intemal environment. To do this it has to be Well insulated. Openings should be orientated and shaded to reduce the heat gain from the sun in summer and to provide sufficient daylight. ,

A thermally massive building Structure or envelope can be used to reduce the effect of heat gains from the sun and occupants and maintain a more constant temperature inside. The best place to put the thermal mass is on the inside of the insulation. This is reflected in the reduced insulation requirements given by ASHRAE 90.1 for exterior insulation.

The reason why it is better to put the thermal mass on the inside is that the interior of a building is usually at a reasonably constant temperature to allow for human amtort. The outside of the building is subject to much larger temperature variations. The role of thermal mass is to keep temperature constant by absorbing peak loads, once it has got hot or cold it can take some time to retum to the average temperature. Placing the thermal mass on the inside of the insulation allows it to remain much closer to the desired intemal temperature.

RECOMMENDATION: For the Pullman Hotel the insulation should be upgradM to meet ASHRAE 90.1. Increasing the insulation beyond this gives diminishing retums measured using the energy saved. To comply with ASHRAE 90.: the insulation values need to be: Walls: U2=0.086 BTU/(hr.ftt.OF) for interior insulation, U=O.l 1 BTUl(hr.fP.OF) for exterior insulation Root U=0.053 BTU/(hr.fP.OF) Floor over unconditioned space: U=0.048 BTU/( hr. fP.OF) Wall below grade: U=O.l BTU/(hr.fP.OF) The maximum glazing percentage, assuming no overhangs are added and clear double glazed units are used, is 24%. This increases to 38% for a shading coefficient of 0.5, assuming that daylighting controls are incorporated. Additional glazing may therefore be added to improve daylight. The maximum skylight area is 3.6% of the gross roof area assuming a,visual light transmission ~0.5.

Note that overall U-values have to mmt the minimum standards shown. U-values am calculated based on both the insulated area and the framed area. Metal framing can mduca the overall U-value by 60% compamd with the U-value of the insulation. Lower U-values conspond to greater insulation.

\~SUN"ONIOUALWOmvuQoc 4 Green Building/Eco-Park

The allowable fenestration percentage changes based on shading, glazing type, the presence of automatic lighting controls and building use. The values given comply for both residential and office use.

Exterior insulation may not be possible for this building because of historic building regulations.

The energy budget is as defined in the appendix tables. This sets a baseline for oftice use. The goal should be to design a building with 60% of this energy use. This should be possible as a result of natural ventilation strategies, good insulation and local control.

\SUN6\1NDNIDUALVt\OmYu.0oc 5 Green Building/Eco-Park

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ave 3.8 4.4 4.9 5.3 5.6 6.0 6.0 5.8 5.3 4.7 3.5 3.2 Max 4.6 5.4 5.9 6.3 6.4 6.6 6.8 6.7 6.7 5.8 4.7 3.8

Min 2.2 , 3.0 , 3.1 , 3.9 . 4.7 , 5.1 , 5.2 , 5.2 3.9 , 3.0 2.3 2.4

3 There are a number of places where solar arrays could be located on the building. These include , shades for south facing windows (historic building regulations permitting) or on the roof. The maximum area of panel on the roof is approximately 4000 square feet. If photovoltaics are used then they should be arranged so that they do not cast shadows on one another as this causes whole sections to stop operating. If water panels are used then shadows will reduce the effedveness but only in proportion to the area of shade.

The approximate efficiency of a polycrystalline photovoltaic array is 13%. The average energy output from a 4000 square foot array is 283kWh per day in June. Assuming a ten-hour day this works out to 28.3 kW. If the power rquirement is 3.5W/sf for,iights and machines then the floor area that can be served is 8000 square feet The most effective way to use photovoltaics is to connect them thrwgh an invgder to the grid and to use two-way metering. The opportunities for doing this in Omaha need to be examined.

If the building is to be used for residential rather than office purposes the electrical power consumption will be much lower and the hot water heating load will be higher. It will therefore be more appropriate to use a mixture of hot water panels and photovoltaics.

RECOMMENDATION: A realistic project goal is to include some solar panels to generate electricity and/or hot water. Parking lighting should be using photovoltaic panels. Green Building/Eco-P ark

Rainwater storage and collection: There is about 4" of rain each month during the summer. If all the rain from the toof is collected this gives a volume of 2000 cubic feet or 14500 US gallons per month. Typical water use within an office building is 25 USG per penon per day, of which 20 USG is for toilet flushing. 14500 USG will therefore provide enough water for 24 occupants for 30 days if it is used for toilets only.

Rain could also be collected from the car park area. Use of this water is likely to be more problematic because of contamination by fuel.

The most convenient place to locate a storage tank is the basement. A pump wil! then be required to lift water to the top of the building so that WCs can be gravity fed. A second tank will be required at the top of the building with a back up supply from potable water supply, WC plumbing will have to be on a separate system to ensure separation of rainwater from potable water.

RECOMMENDATION: Water collection should be examined more closely during design. The cost of the additional plumbing and tank should be assessed during design and compared to the water supply rates. If the storm water system in the area is close to capacity then the possibility of storage may be more attractive.

\\SUNg\lNONIOUALVdOm.h..dQ: 7 I Green Building/Eco-Park

Trombe Walls: The purpose of a trombe wall is to collect solar heat during the winter and to use the heat to achieve camfortable conditions within the building. Trombe walls are most useful in areas with many heating degree days and good Winter sunshine. There can be problems associated with trombe walls in ~e summer because they continue to collect heat

A trombe wall is a massive south-facing wall with a glass wall in front of it. The cavity between the glass and the solid wall is ventitated. In the summer the air is used to remove heat from the wall and is drawn from the outside and released back to the outside. In the winter the air is used to collect heat from the wall and is recirculated from the heated room through vents at the top and bottom.

There is a large south facing wall at the Pullman hotel which could be used as a Trombe wall. The following items would have to be provided: a glass outer fapde, separated at each floor level, ventilation holes to the rooms at high and low level with automatic dampers and insulation on the inside of the wall. This wall is currently a party wall and solar rights would have to be established before installing a Trombe wall.

Trombe walls are appropriate for residential and very low load spaces in Omaha. There is likely to be a greater energy benefit if windows are added to the south wall to improve daylight and natural ventilation. . REC 0M M EN DATl0 N : ;e Address the issue of solar and light rights for the south wall. For office space additional windows will be more useful than a trombe wall. For residential space consider a trombe wall. If the program remains undefined additional windows will result in more flexible space.

8 Green Building/Eco-Park

Natural Ventilation Strategies: There are two mechanisms for natural ventilation: buoyancy effects due to temperature differences and wind. It is usual to design openings and air paths for a natural ventilation system based on buoyancy Only because there is no guarantee that the wind will be blowing at all times and because the effect of wind significantly outweighs the effect of buoyancy.

Buoyancy effects are increased if there is a large difference in height between inlet and outlet, or if there is a large temperature difference between inside and outside air conditions. Natural ventilation is usually used to limit temperature difference in summe; so that increased ventilation rates are usually achieved by-increasing the height difference between inlet and outlet

The existing building was designed to be naturally ventilated. Nearly all points on the floor plate are within 20' of an operable window. (20 is the limit set by Califomia Title 24 for maximum distance in naturally ventilated buildings). The windows can open at both top and bottom allowing thermally driven single sided ventilation.

To allow the building to continue to be naturally ventilated the intemal loads should be limited. This means installing efficient lighting which is tumed off when not needed and using efficient office machinery with automatic sleep modes. The office space should also be kept as free from partitions as possible and ceiling heights maintained as high as possible.

It would be possible to use the existing outside stair tower to the east as an atriumlstack. This is not recommended because it reduces the flexibility for intemal layout in NE comer of the building by blocking some of the windows. This block would mean that the NE comer would have to be completely free of partitions. There are also code difficulties connecting the floors together in this * way. The atrium would act as a shaft connecting all floors so that the openings would have to be fire protected.

\\SUN6\1NDNIDUMVc\OmHldoc 9 Green Building/Eco-Park

RECOMMENDATION: Maximise use of existing windows for natural ventilation, open up windows that are cunentjy blocked. Organise interior layout to allow every room to have a window. Make intemal floor plan as open as program allows. Consider the use of stack ventilation on the north wall of the existing stair. Provide separate stacks for each floor and terminate at roof level. Shape the tops of the stacks to encourage winddriven ventilation using venturi COGS.Consider installing an exhaust + 1 fan to increase ventilation rates and therefore cooling capacity in the mid-season.

Note that natural ventilation mechanisms are usually too weak to drive air through filters. This means that indoor air will contain as much particulate matter as the outdoor air. /

v2 ,. J dl I'

. \\SUNB\INDNIDUALUf3Om.hLQoc 10 Green Building/Eco-Park

Mechanical Systems Heating and cooling systems will be required. There are many options for this but the building is ___ small so very complex systems will not be financially viable or will require too much space.

~ The most energy efficient is to provide central heating and cooling equipment in the basement - and to pipe hot and chilled water through the building. Local fans would then allow the occupants to control the heating and cooling at each location These fans should be located on the outside wall either above or below the window. An altematie method would be to use air-to-air heat pumps mounted in the windows. This is noisier and less efficient

Cooling can be achieved using an evaporatively or aircooled chiller. This needs to be located in an outside shaded area. The refrigerant shoukl be 134a as this has no HCFC content

Heating can be achieved using a boiler. This could bum building waste or natural gas. The kind of waste that could be bumt includes general household waste that cannot be recycled or composted for use in the landscape. It is likely that natural gas will prove most cost effective but an investigation of altematives should be carried out \ Minimum fresh air would be provided through a wall opening to the local fan when extra cooling or heating is required. . .'

11 1 Green Building/Eco-Park

Appendix: Establishing annual energy budgets

__ Prototype Building according to Ashrae 90.1:

The prototype building is 103 R x 41.2 R x 65 R tall with long axis facing West and East.

Gross Floor Area 21218 sqft Roof area 4244 sqft

The following values are taken from Table 8A of Ashrae 90.1:

Roof U-value 0.053 Btu/(sqfi*hr"F) Wall U-value 0.082 BW(sqft*hr'"F) Window U-value 0.59 BW(sqft*hP"F) Shading Coefficient 0.65

These intemal loads are based on v-es taken from standard Ashrae 90.1:

# of people ( 275 sqft/penon) 77 Sensible (230 Bt~dh'person) 17710 Btu/h Latent (190 Btu/h'person) 14630 BNh

Lighting load (1.72 W/sqft) 36495 Watts 124514 BNh

Internal Heat gains 156854 BNh

Infiltration 0.038 cfm/sqft of gross extenor wail area

Infiltration 570 cfm Green Building/Eco-Park

Heat loss or gain due Roof Wall Window Window to Total Heat loss Envelope Envelope Heat Envelope Solar Heat infiltration or gain Heat loss or loss or gain Heat loss or loss or (sensible) including Month HDD COD gain (Btu) (W gain(8tu) gain (Btu) Btu intemal (Btu) Jan 1381 0 77029250.1 421 147903.9 757754700.0 210779390 1466711244.0 Feb 1094 0 55115741.0 301 338501.e 542186400.0 150816245 1049456887.8 Mar 846 0 47188085.1 257995023.0 464200200.0 129123363 898506670.8 APr 414 5 22347137.1 126252883.6 227161800.0 6 1149705 43631 1525.7 May 155 76 8645571.2 4~743798.4 a230500o.o 23657354 16035 1723.2 Jun 11 21 a 11767333.1 64336439.0 115758000.0 52456.. 32199603 261706335.2 Jul 0 356 19856924.7 108565281.5 195337200.0 51995 54335599 416994797.7 Aug 11 286 15952473.2 8721 ~5.6i~692a200.0 50187 43651633 342650274.1 SeP 90 a5 4858073.3 26560915.2 47790000.0 1329341 4 92502402.6 OCt 364 11 20303 147.7 11 1004950.8 199726800.0 55556624 386591522.7 Nov 788 0 42535130.5 232555568.6 418428000.0 116391226 809909925.2 Dec 1258 0 70168571.0 383637989.2 690264600.0 192006135 1336077295.4

Total Heating 66370 19 197.5 Total Cooling 1021351 407.0

.. _. Grenn Building/Eco-Park

Assumptions made Fuel type: Natural gas (1000 Btu/std cuft) Efficiency : 80% ( Based on Califomia Non-residential Standard, Title 24)

Quantity Outside Interior Total Heat of Fuel Temperature Temperature loss or gain Required Month I "F HDD "F BWh std cuft Jan I 21 1381 70 587287.0 140691.2 Feb 27 1094 70 515374.0 104896.6 Mar 38 846 70 383534.0 86187.28 APr 52 414 70 215738.0 44657.77 May 63 155 70 83898.0 16719.67 SeP 66 90 70 47942.0 9708.255 Oct 54 364 70 191767.0 37082.94 Nov 39 788 70 371549.0 80278.55 Dec 27 1258 70 5 15374.0 128160.3

Total 648382.6

Required fuel for the year is 648,383 cuft of natural gas,based on a Bhrs/day occupancy. The proposed building energy consumption for heabing must be less or equal to the prototype building energy consumption stated above.

EER 9.20 BHMatts (Taken from California Non-Residential Standard, Title 24)

Total Cooling Load: 1021351407 BTU or 48136.083 BWsqft for the year

Required cooling energy consumption: 5232.18 Watts'hrlsqft 5.2 WhrisqR