C o m m e n t a r y The Proof Is Performance How Does 4 Measure Up?

B y A d a m W. Hinge, P. E . , M e m b e r A S H R A E , a n d D o n a ld J. Winston, P. E . , M e m b e r A S H R A E

he road to high per- From this perspective, we’ve experi- T enced firsthand the all-too-common forming buildings is paved frustration of a building’s energy per- formance not meeting design expec- with high expectations— tations, particularly a new building’s energy savings projection that over- but, ultimately, it is mea- states actual performance. Across sured performance that the high performing building indus- try, these unrealistic energy perfor- shows how energy efficient mance goals have come from (among other things) inadequate modeling a building really is. As own- practices, failure to include opera- tions staff in goal setting or accu- ers and managers of more rately communicate the design intent to the staff and lack of adequate than 8 million ft² of Class budgets for commissioning, evalua- tion and ongoing benchmarking. A office space in midtown As more actual energy perfor- mance data become available on , including the high performing buildings, clearer Condé Nast Building at and more realistic expectations will help to establish confidence within , The Durst the building design and construc- tion industry about costs and sav- Organization understands ings. By providing some of our data, observations and experience working this concept well. through design, construction and operation of high performing build- ings, specifically using the 4 Times Square building as an example, we hope to encourage others to share actual energy performance operating results and lessons learned earlier, Condé Nast Building at 4 Times Square.

3 0 H i g h Performing Buildings Winter 2008 The Times Square redevelopment district requires a specified amount of exterior signage and lighting.

rather than later; this helps everyone avoid making the same mistakes as the high performing building move- ment gains momentum.

Defining and Measuring Energy Performance Energy performance in buildings can mean many different things. Energy intensity, or energy use per unit of floor area, is one common measure of building energy performance. The U.S. Environmental Protection Agency (EPA) ENERGY STAR® building pro- gram, with its Portfolio Manager rat- ing system, measures and compares building energy performance through adjusted energy intensity. However, energy intensity must be balanced against other performance criteria and project requirements—for example, a building with no lights, air- conditioning or mechanical ventilation will have extremely low energy inten- sity, but will not adequately serve the needs of building occupants. Building energy performance can also be measured as compared to a threshold, usually with respect to an energy code or standard. While this is the most common metric used for new building energy performance, a build- cess other than conditioning spaces end users in new buildings, such as ing that has been designed to perform and maintaining comfort and ameni- server rooms, lab equipment, cook- at a significant reduction below the ties for the occupants of a building.” ing or restaurant equipment, security energy code may not compare well to For example, many design teams systems, building control systems, a similar building where performance will gather energy performance fire safety systems, computers, print- is measured by energy intensity. data for energy-efficient buildings ers, copiers and some plug loads. In addition, many earlier codes and by comparing only the systems that Many of these excluded loads oper- rating schemes did not take process the design team controls—such as ate 24/7; so while an energy savings energy into consideration, defined envelope insulation value, percent- calculation will state significant in ANSI/ASHRAE/IESNA Standard age glazing, solar shading, chiller energy savings, the real energy use 90.1-1999, Energy Standard and boiler efficiency, fan and pump of a new building may be much for Buildings Except Low-Rise motor efficiency, installed lighting higher. These details need to be Residential Buildings, as “energy power density, and system selec- considered when setting goals and consumed in support of a manufac- tions. This excludes the process reporting both projected and actual turing, industrial, or commercial pro- energy elements, some of the biggest energy performance.

Winter 2008 H i g h Performing Buildings 3 1 c a s e s t u d y

The Condé Nast Building at 4 Times Square

An early, high-profile building that cally over the last several years, we calculates to be the annual site is often cited as being one of the reviewed energy use at 4 Times energy intensity for an average- pioneers in the high performing Square and compared it to other rated building (50th percentile) with building movement is our Condé buildings in our portfolio as well as the use characteristics of 4 Times Nast Building at 4 Times Square in the broader population of peer build- Square. Source energy includes the New York . In response to grow- ings in New York. energy consumed at the building ing interest in the measured energy Table 1 shows how the 4 Times itself—or the site energy—plus the performance of green buildings, as Square energy intensity, in kBtu/ft² energy used to generate, transmit well as increased interest from ten- per year, compared with other Durst and distribute the site energy. ants about relative energy use/costs buildings, and with what the EPA as energy prices have risen dramati- ENERGY STAR® Portfolio Manager

T a b l e 1 C o m p arison of 4 T i m e s S q u a r e E nergy Performan c e t o B e n c h m a r k s

kBtu/ft per year The table demonstrates that 4 Times Square • the principal tenants of the building, a pub- is significantly more energy efficient than the lishing house and a law firm, both have signifi- Source Site median office building, but that cant after-hours operations, often until 1 a.m. Energy Energy it is not the lowest in energy intensity among The building is available for tenants 24/7. the Durst portfolio. Some of the reasons for • A broadcast antenna atop the building with 4 Times Square 244 120 higher energy intensity at 4 Times Square transmitter facilities for radio and television relative to other Durst buildings include: stations uses significant process energy. • significantly higher amounts of outside air Some of these facilities operate 24/7 and Best Durst Building 213 76 (twice the prior New York City industry stan- require continuous operation of the building dard practice) are delivered to the tenant cooling plant. floors by a dedicated outside air system. Durst Fleet Average 239 107 • two corporate cafeterias with commercial This additional outside air requires additional kitchen facilities use significant amounts of fan and chiller energy use to deliver and process energy. 50th percentile per condition the air. In addition, the outside air • finally, direct gas-fired absorption chillers, ENERGY STAR ® (with the is filtered to a higher level (85%) than older 366 180 selected by the design team primarily for use characteristics buildings with the additional filter resistance, of 4 Times Square) adding to fan energy consumption. their lack of impact on the electrical grid, favorable operating costs, and lack of harm- • the Times Square redevelopment district ful refrigerants, are not the most efficient requires a specified amount of exterior sig- choice with respect to overall net site or nage and lighting as the minimum, process source energy use. If the building had been energy that was not taken into consideration built with electric chilling, the site energy while setting performance goals. This lighting intensity would be substantially lower. consumes substantial additional energy.

3 2 H i g h Performing Buildings Winter 2008 info.hotims.com/15939-12 B u i l d i n g A t a G l a n c e

Building Name Condé Nast Building Location 4 Times Square, New York City Size 1.6 million ft² Managing Energy energy modeling tools are very Started 1996 Performance Expectations good at modeling standard HVAC Completed 1999 In any rapidly growing industry, systems, but it can be more of a Use office space performance expectations are challenge for less experienced Cost $270 million reported at a rate that outpaces modelers to predict the energy use Distinctions the first green high-rise publication of actual results, and of advanced green building compo- in the United States. are often inflated. In the case nents such as natural ventilation, of green buildings and actual atria, displacement ventilation, operating performance, potential chilled beams, and double façades, B u i l d i n g T e a m savings are being oversold in some among others. instances. Another element that can result Owner the Modeling can be one major issue in low building performance is a Architect fox & Fowle Architects in understanding why energy disconnect between design and Mechanical Designer expectations are not being met. operation—at the time of design Other Key Players tishman Construction Potential inaccuracies of energy and modeling predicted energy modeling are well known, nonethe- performance, optimal control less common errors persist. Most strategies and schedules often

3 4 H i g h Performing Buildings Winter 2008 4 Times Square was the nation’s first green high-rise.

are assumed that do not occur in operation. For example, day- lighting strategies might assume that artificial lighting is dimmed or turned off, while operators or occupants often do not understand the control systems and so do not use them as intended. Also, lack of commissioning can result in systems that are not operating as designed, frustrating operators and occupants. To manage expectations for energy performance, the design team must understand operational expectations from the beginning of the project. In one recent example, the new

L e s s o n s L e a r n e d

Based on our experience with the 4 Times and installation costs were much higher than Commissioning and Owner Involvement Square building, a variety of changes have expected. Finally, the waste heat recovered At 4 Times Square, commissioning played an been made in the design of our next project, from them is low-grade and not very useful. important but limited role in identifying short- the Bank of America Tower at One Bryant At One Bryant Park, instead of a fuel cell, a comings in the design, along with construc- Park, currently under construction and gas turbine is being used to achieve energy tion deficiencies. This allowed the building expected to be completed in 2008. From production goals in a more dramatic way. The to become fully operational much earlier fol- the lessons learned at 4 Times Square, a turbine is the first installation of its kind at a lowing completion than other buildings in the number of things are being done differently at commercial office building and is expected to Durst portfolio. But, because the team was this new 2 million ft² tower being built on the produce 4.6 MW, providing about 70% of the engaged during the final stages of construc- same block. building’s annual energy needs. In addition, tion, the process was less efficient than it the waste heat from the turbine will be used could have been. Fuel Cells the 4 Times Square design to heat and cool the building. At One Bryant Park, we engaged the commis- includes two 200 kW natural gas-powered sioning team much earlier during the design phosphoric acid fuel cells. The cells currently Photovoltaics A similar series of problems process and before construction began. This produce about 10% of the annual electric occurred with the building-integrated photovol- was to ensure that the building will operate energy used in the building. taics installed at 4 Times Square. After see- to design intent and efficiency level from day After the building was operational and ing that installation costs were much higher one. As an additional benefit, early involve- actual production results could be recorded, than expected and that production rates were ment allows the commissioning agent access we realized that, though fuel cells work, from much lower than expected due to the vertical to systems that would normally be inaccessi- a fiduciary standpoint this application and orientation of the photovoltaics in the build- ble and hidden by the time the typical sched- design was not the best use of the technol- ing’s façade, we realized that this technology ule would commence. The commissioning ogy. The two fuel cell units consume a large was not best applied in a Manhattan high- team is also much larger than the team at 4 amount of space that is out of proportion to rise office building. At One Bryant Park, we Times Square, allowing for increased system the actual amount of power being produced. resisted the desire and pressure to include testing, surveillance and inspection. Partly In , the price of this office building-integrated photovoltaics. due to the commissioning process, we (as space is at a premium. Also, the units have owners) have also been much more involved turned out to be very maintenance intensive, in establishing design intent and goals and have had much more oversight during the design and construction process.

Winter 2008 H i g h Performing Buildings 3 5 two buildings, and vacancy levels in the old city hall. This press coverage clearly indicates the need to better manage expectations to avoid damaging news stories. This type of out-of-context information can erode confidence in the industry and discourage other owners and managers of high- profile high performing buildings from releasing actual energy performance data.

Conclusion High performing buildings need to provide healthy, productive and safe places in which to live and work. Clients require energy efficiency, improved indoor envi- ronment, and innovative design, and it is an undeniable fact that T h e D u r s t O rganization there are trade-offs between these Waste heat from a gas turbine will performance demands. Clearly the The Durst Organization owns and man- be used to heat and cool the Bank of most effective way of advancing ages nearly 8 million ft² of Class A office America Tower. space in midtown Manhattan, including the building construction industry the Condé Nast Building at 4 Times towards a sustainable balance is Square. This 1.6 million ft² building, through rational analysis of the which opened in 1999, was the nation’s first green high-rise. actual performance. By continuing to disclose perfor- Currently, Durst is building the Bank of America Tower at One Bryant Park, a new Seattle City Hall, which received mance data and lessons learned 54-story, 2.1 million ft² crystalline struc- a U.S. Green Building Council about projects, such as the 4 Times ture that aims to be a LEED® Platinum (USGBC) LEED® Gold rating in Square Building, we can help to . Additionally, Durst has recently completed two green high-rise 2003, became front-page news move each other forward on the residential towers in Manhattan—the in the Seattle Post-Intelligencer: road to high performing build- Helena (LEED® Gold) and the Epic (tar- “Seattle’s New City Hall is an ings—with good intentions and geted to be LEED® Silver). Energy Hog: Higher Utility Bills high performance. • Durst has been an EPA ENERGY STAR® Take the Glow Off Its ‘Green’ partner since 2002 and regularly tracks energy performance through EPA’s Designation” (Seattle Post- Portfolio Manager. Intelligencer, July 5, 2005). The new city hall does use more energy than the old city hall, A b o u t t h e A u t h o r s but for a variety of valid reasons including much greater ventilation Adam Hinge, P.E., is the managing direc- levels, different uses between the tor of Sustainable Energy Partnerships. Don Winston, P.E., is the director of tech- nical services for The Durst Organization.

3 6 H i g h Performing Buildings Winter 2008 info.hotims.com/15939-5