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This article was published in High Performing Buildings, Fall 2011. Copyright 2011 American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. Posted at www.hpbmagazine.org. This article may not be copied CASE STUDY MANITOBA HYDRO PLACE and/or distributed electronically or in paper form without permission of ASHRAE. For more information about High Performing Buildings, visit www.hpbmagazine.org.

Manitoba Hydro, the province’s sole energy provider, began planning for a new, energy-efficient headquarters in 2002. The design team soon realized that the extreme climate of Winnipeg, Manitoba, actually provided a rich opportunity for harnessing the abundant solar and HARNESSING wind energy to operate the building using more passive systems. he program called for realized that the climate challenge Design Charettes a 690,000 square foot actually presented an opportunity The design charette is a critical tool building on a full block to reduce energy use and create a in the IDP to advance integrated in downtown Winnipeg healthy workplace. thinking and solutions. Fifteen toT accommodate 1,800+ employ- building form options were gener- ees. One goal was to reduce energy Project Charter ated for evaluation and testing CLIMATE consumption 60% below Canada’s Manitoba Hydro mandated the and three options were selected BY BRUCE KUWABARA, THOMAS AUER, TOM AKERSTREAM, GLEN KLYM Model National Energy Code project be designed, developed for detailed development and Building (MNECB). Manitoba Hydro and delivered using a formal inte- analysis to test passive efficiencies,

WITH MARK PAULS, KAEL OPIE AND JOHN PETERSON also wanted to create a landmark grated design process (IDP). An building with signature architecture essential first step of theIDP is to BUILDING AT A GLANCE that contributes to the revitalization determine the project charter. The EDITED BY AMANDA SEBRIS of downtown Winnipeg. However, project charter clarifies the project Name Manitoba Hydro Place Architecture is a powerful the primary purpose of the build- goals and is continually referenced Location Winnipeg, Canada reflection of civilization. It is the ing was to create a healthy, sup- for every major design decision. Owner Manitoba Hydro responsibility of every architect portive workplace for Manitoba Manitoba Hydro’s project charter Principal Use Corporate Head Office to make buildings that enrich the Hydro’s employees. contained six core goals. Includes Office space, meeting world, not deplete it. A building Winnipeg’s extreme climate was rooms, conference center. 1. To create a supportive workplace initially perceived as a challenge Employees/Occupants 2,000 that thinks and breathes on its environment for the employees of to the energy reduction goals. The own serves both as a function Manitoba Hydro; Occupancy 100% city’s temperature annually ranges of civilization as well as a 2. To create an energy-efficient design; Gross Square Footage 823,535 70°C (126°F), from –35°C (–31°F) 60% reduction in energy consumption Conditioned Space 695,241 contributing member within it. from the MNECB; in the winter to +35°C (95°F) in Distinctions/Awards – BRUCE KUWABARA the summer. However, Winnipeg 3. T o create a design that achieves a LEED Gold certification; 2009 Council on Tall Buildings and also receives more sunlight than Urban Habitat — Best Tall Building most major Canadian cities, and 4. To develop signature architecture (Americas) integrated throughout the building at 2010 ArchDaily Best Office Building has an unusual abundance of strong different scales from street level to the roof; 2010 Royal Architectural Institute of © Gerry Kopelow southerly winds. The building team Canada Urban Design Award 5. Urban design — to achieve a high 2010 American Institute of Architects Opposite The solar chimney at Manitoba level of urban integration to revitalize COTE Award Hydro Place (in the forefront of the the downtown; 2010 Engineers Canada Award building) passively exhausts air in sum- 6. To achieve a cost-effective building mer, spring and fall. In winter, fans draw design solution that has measurable Total Cost $283 million CDN the exhaust air down to ventilate the benefits to Manitoba Hydro in terms of parking garage and for recovery of comfort, operations, and maintenance. Cost Per Square Foot $400 CDN exhaust heat. The building reduces energy use by 60% over the Model National Substantial Completion/ Energy Code of Canada without using Occupancy Fall 2009 on-site renewable energy.

6 HIGH PERFORMING BUILDINGS Fall 2011 Fall 2011 HIGH PERFORMING BUILDINGS 7 © Tom Arban © Tom daylighting, and climatic impact stacked atriums due south to capture west office lofts are splayed open at through computational fluid dynamics, Winnipeg’s abundant sunlight during the south end and separated by win- wind analysis and energy modeling. the winter and strong southerly winds. ter gardens that maximize solar heat The final solution is a hybrid of It was dubbed the “Solar Tower” and gain. The lofts meet at the north end formal process and serendipity. The became the preferred option. of the tower, reducing direct northern energy consultant rotated one of the The tower form itself functions as a exposure and minimizing heat losses. splayed tower schemes to position the passive solar collector. The east and Double Façades A glass tower in Winnipeg’s extreme climate was ironically logical. When it is extremely cold, it is also very sunny, ideal for solar gains. The reduction in heating demand for Manitoba Hydro Place is largely due to a high performance double façade curtain wall design.

Above Atria at the north end of the tower collect exhaust air from adjacent floors. Dampers at the chimney intake are used to balance the stack effect throughout the tower height. This exhaust plenum doubles as a break space for employees. Left The Public Galleria connects the streets through the entire city block, creating a public pedestrian throughway. The galleria also

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HPB.hotims.com/37996-2 and outdoor views. By introduc- approach at Manitoba Hydro Place, responsible for providing 100% fresh ENERGY AT A GLANCE KEY SUSTAINABLE FEATURES ing buffer façades on the east-west and has become an iconic image of air every day throughout the year. Annual Energy Use Intensity (Site) faces, and by expanding the south downtown Winnipeg. In the winter, fan coils fill the Water Conservation 29.3 kBtu/ft façade buffer zones to act as winter winter garden with outside air pre- Low flow fixtures Dual-flush water closets 2 Natural Gas 6.8 kBtu/ft gardens, excellent daylighting and Arban © Tom ‘Lungs’ of the Building heated to 5°C (41°F). The expansive Waterless urinals Electricity 22.5 kBtu/ft2 views can be maintained while also The three stacked, six-story high win- south-facing curtain wall (more than Rainwater and condensate capture 2 and storage for irrigation Annual Source Energy 82.3 kBtu/ft2 supporting energy efficiency. ter gardens — large, unconditioned 400 m² [4300 ft ] in area) allows The double façades are the most spatial volumes — are unique in the Winnipeg’s abundant winter sun to Recycled Materials Annual Energy Cost Index (ECI) 24% of construction materials overall, $0.50 CDN/ft2 apparent example of the climati- context of hermetically sealed North provide the remaining sensible heat. including: Concrete (73%) Savings vs. MNECB Design cally responsive approach used to American office buildings. They Humidification is provided by Reinforcing steel (100%) Building 60% make Manitoba Hydro Place energy are the “lungs” of the building and a 24 m (79 ft) tall water curtain Access floor (17%) Savings vs. ASHRAE Standard 90.1-2007 efficient. The east and west façades Shades (60%) Design Building approximately 52% operate in three main modes. In the Interior demountable walls (82%) SITE PLAN Carpet tiles (45%) Heating Degree Days 10,260 (base 65°F) winter, the façade is sealed tight and Outdoor decking (90%) Cooling Degree Days 326 (base 65°F) acts as a solar collector. Without Bike racks (25%) the assistance of active heating, the Acoustical wall treatment (85%) interstitial space regularly reaches Daylighting 85% of regularly occupied area with WATER AT A GLANCE 20°C (68°F) — even with outdoor daylight factor above 2% temperatures below –25°C (–13°F). Tall and narrow lofts (3.1 m × 11.5 m) Annual Water Use 2,660,585 gallons This significantly reduces heat losses with stepped double façade design and an open floor plan allows excel- through the envelope. lent daylight autonomy In the summer, hundreds of oper- Individual Controls This contradicts the conventional able windows on the outer (double- Manually operated window vents approach to an energy-efficient glazed) façade open and allow wind Exterior shading (extension and tilt) Lighting (fully dimmable)

envelope, which increases opaque and convective air patterns to ventilate © Eduard Hueber Other Major Sustainable Features Top The double façade curtain wall con- areas and insulation on the build- the double façade. Automated louver Deconstruction of existing site (more than sists of a double-glazed outer façade and a 90% of material diverted from landfill) ing exterior. A conservative glazing shades within the curtain wall cav- single-glazed inner wall, which is a reversal Demand ventilation for variable ratio would compromise two key ity control glare and heat gain. This of typical installations. It acts as a high-per- occupancy areas formance thermal buffer in the winter, while qualities of a high-quality indoor ensures that cooling demands are not Balanced geothermal field (equal maximizing the quality of interior space and heating and cooling on annual basis) environment: maximum daylight increased by the façade. protecting motorized shading devices. Plug-in hybrid fleet vehicles for employees Below A green roof, made up of natural PERCENTAGE OF HOURS IN NATURAL VENTILATION prairie grasses and ceremonial sweet grass, covers the podium. When necessary, (35% ANNUALLY) it is irrigated with rainwater collected on composed of mylar ribbons. The site, and condensate from the fan-coils. ribbons maximize water feature surface area to encourage moisture During the shoulder seasons, the exchange, and water is heated to outer façade is opened and employees 32°C (90°F) for humidification. are asked to open the manually oper- In the summer, the winter garden ated windows on the inner curtain fan coils are disabled, and operable wall. The outer façade is controlled vents bring fresh air into the build- automatically based on indoor and ing. Sun-tracking louver blinds are outdoor conditions, including out- used to manage solar heating, and the side and interstitial air temperature, temperature of the water feature is

humidity, light levels, and wind speed. © KPMB Architects dropped to 10°C (50°F) for dehumid- The decision to angle the tower on the site led to the creation of a uniquely shaped park The modulating curtain wall is a visi- on the southern portion of the site—now a popular green space in downtown Winnipeg. ification. Throughout the year, natu- ble example of the climatic-responsive This, in addition to ground-level retail tenants, adds to the vibrancy of the area. ral stack effect distributes fresh air

10 HIGH PERFORMING BUILDINGS Fall 2011 Fall 2011 HIGH PERFORMING BUILDINGS 11 throughout the volume of the space, DOUBLE FAÇADE: WINTER which is then drawn into the raised floor plenum at each of the six floors connected to the winter garden. Displacement ventilation is used to efficiently and effectively distribute fresh air. An “air highway” directs fresh air under the raised floor from south to north along the office lofts. The air, slightly cooler than space temperature, spills out of floor level vents to flood the office space. Stale © Gerry Kopelow air is naturally drawn towards the Above The free heating and passive airflow of ventilation air in the winter gardens north end of the office, driven by allow for 100% fresh air distribution with buoyancy forces and the pull of the minimal energy usage. The fresh air and daylight are ideal for casual meetings and solar chimney. The solar chimney regularly host lunch-hour fitness classes. passively exhausts the air in the sum- Left Incoming ventilation air is condi- mer. In the winter, fans at the base of tioned by 79 ft tall winter gardens, known the solar chimney draw exhaust air as the “lungs” of the building. These spaces rely on passive solar heating and down to both ventilate the parking shading to control air temperature, while garage and recover exhaust heat. a water feature manages humidity. The winter garden height was chosen to allow The interstitial space in the double façade quickly heats up due to solar gains — the stack effect to distribute fresh air especially in the winter. During a typical week of –25°C outdoor temperatures (green line), Thermal Comfort naturally to each floor. the façade around the building is heated to 20°C (blue line) on sunny days (red line). © Eduard Hueber Heating and cooling is achieved primarily through the use of active TOWER OFFICE SECTION radiant slabs. More than 180 miles of plastic tubing is embedded in the MANITOBA HYDRO LIGHT LEVEL MARCH 2011 TYPICAL TOWER OFFICE SECTION - east and west faces offer double skin facade with occupant concrete, and slab temperatures are controlled natural ventilation - oor to ceiling height of 3.31m (10'-10") - oor to ceiling glazing, typical modulated between 20°C and 23°C - overhead radiant heating and cooling - air and services distributed through raised access oors (68°F and 73°F) to maintain comfort SPATIAL OFFICE CONCEPTS BY KPMB F IT-UP IMPLEMENATION AND DEVELOPMENT BY MC/IBI throughout the year. The thermal JUNE 12, 2008 SCALE 1:250 contained spaces open mass of the all-concrete building workstations also minimizes temperature fluctua- tions throughout the occupied hours, and allows heating and cooling systems to be turned off on evenings

oor to ceiling glazing and weekends. - optimal daylighting glass transom - user operated natural ventilation The passive design features com- - retractable / adjustable solar shading enclosed spaces demountable partition bined with the efficient heating supply system, including a ground- CONTAINED SPACES 8'-0" demountable solid & glass partitions source heat pump, exhaust air heat ENCLOSED SPACES 8'-0" demountable solid & glass partitions, with glass recovery, and condensing boilers, transoms to ceiling raised access oor - air supply and services reduce energy use for heating to only CORE Integrated daylight sensors help reduce office lighting energy use. Even on an overcast 2 elevators, services, & storage 28 kWh/m² (3 kWh/ft ) annually. This day with minimal brightness, lighting energy (red line) quickly decreases as daylight (blue OPEN WORK STATIONS 50" tall panels line) increases. is a significant drop from an annual typical heating load of 250 kWh/m² © KPMB Architects

12 HIGH PERFORMING BUILDINGS Fall 2011 Fall 2011 HIGH PERFORMING BUILDINGS 13 BUILDING SYSTEMS OVERVIEW LESSONS LEARNED

Office Acoustics building sequences that only can be tested from nearly all other implementations. This Manitoba Hydro Place shows that energy during a brief seasonal window once a year. was a result of concerns about frost forma- efficiency can be complimentary to a high- An entire year may be required for system tion in the winter. To account for summer quality indoor environment. For example, the commissioning. conditions, the single inner glazing has an glass double façade is critical to the energy The lighting system proved to be the most exposed pyrolytic low-e coating to minimize concept for the building, but also offers difficult system for commissioning. The radiant effects. occupants good daylighting, access to views office lighting system, while elegant in its and personal control of natural ventilation. form and functional as an energy-saving Optimization Stage However, the abundant glazing, in combina- device, provides little feedback to building Manitoba Hydro is committed to ongoing tion with the exposed concrete ceilings, operators. All other building components study and optimization of Manitoba Hydro results in many hard surfaces. These hard provide a wealth of real-time information Place. Since occupancy and the end of the surfaces create an acoustical environment that can be used to troubleshoot problems commissioning phase, building sequences different from traditional offices, which often and optimize sequences. The lighting and setpoints have been regularly updated. feature ceiling tiles. Accordingly, some occu- system, however, only allows one-way com- Examples of the more significant sequence pants were initially concerned about speech munication to the device. Ideally, future changes from the original design include: privacy and acoustical quality. generations of integrated lighting systems • Incorporating outdoor humidity into the A sound-masking system installed within will include feedback from the daylight sen- natural ventilation sequence to ensure the raised floor has proven beneficial—the sor of each fixture, real-time energy data that the building enters dehumidification white noise generated mimics HVAC noise and other information. when appropriate. and provides aural distraction to employees. • Modify geothermal field pumps to In addition, acoustically private meeting Double Façade in a Cold Climate control speed as a function of return rooms were added on each floor. In general, Manitoba Hydro Place is among the first temperature from the field (instead of a though, employees have adapted to a qui- large-scale implementations of a double pressure setting). eter environment, and communicate in a façade in a cold climate. This is a technol- • Increase radiant slab zoning resolution to manner suitable to the environment. ogy still viewed largely with a degree of reflect different solar gains at north and skepticism in North America. The double south tips of the office tower. Commissioning Challenges façade at Manitoba Hydro Place was stud- • Use low temperature heating water sup- Unique commissioning challenges are ied extensively prior to implementation, plied by the ground-source heat pump to associated with a building that responds using computational fluid dynamics, several displace the high temperature system to the climate. The biodynamic nature of mock-ups and many thermal models. The from the condensing boilers in the shoul- Manitoba Hydro Place means that the build- analysis led to several unique characteris- der seasons. ing responds very differently to Winnipeg’s tics of the façade. Most notably, the single four distinct seasons. As such, there are glazing is located on the inside, a departure

BUILDING TEAM (23 kWh/ft2) in Winnipeg where heat- For common areas, feature light- Client Manitoba Hydro ing degree days are typically above ing is programmed based on outdoor Architects Kuwabara Payne McKenna 10,000 (base 65°F). light levels. Currently, the lighting Blumberg Architects (design architects), energy is reduced by 44% from the Smith Carter Architects and Engineers MNECB reference building. This is (executive architects), Prairie Architects Daylight Autonomy (advocate architect) A narrow (11.5 m [38 ft] wide) loft expected to drop further as recent Energy and Climate combined with a 3.1 m (10 ft) ceil- sequence changes tying exterior and Transsolar Energietechnik GmbH ing height and open floor plan pro- common area architectural lighting Contractor PCL Constructors Canada vides natural daylight throughout to outdoor light sensors are reflected Structural Engineer nearly all of the occupied areas. The in metered data. Crosier Kilgour/Halcrow Yolles double façade design is “stepped” Mechanical & Electrical Engineer to maintain a good daylighting Building Management Earth Tech Canada angle, and low-iron glass provides System (BMS) Lighting Design Pivotal Lighting Design excellent visible transmittance. T5 The building management system Landscape Design high output fixtures supplement the (BMS) uses prevailing conditions Hilderman Thomas Frank Cram, daylight through uplighting, and the (temperatures, radiation, wind, pre- Phillips Farevaag Smallenberg use of an integrated daylight sensor. cipitation) for real-time integration of © Brian Christie

14 HIGH PERFORMING BUILDINGS Fall 2011 Fall 2011 HIGH PERFORMING BUILDINGS 15 architecture and the individual systems for comfort and efficiency. Two on-site weather stations collect climate data, which is manipu- lated using building sequences into commands for various control points (operable windows, shade positions, slab temperatures, etc.). These sequences are continually

optimized as improved occupant © Gerry Kopelow comfort and energy savings are identi- The office tower is situated on a three-story podium scaled to the surrounding area. fied. For example, a nighttime build- between 200 to 300 ppm above The tower has been shifted from the street ing flush program was implemented outdoor levels throughout the grid to face exact south and maximize when it was observed that downtown occupied hours. passive solar heating. Winnipeg often has sufficient daily In addition, Manitoba Hydro Place temperature swings in the summer. encourages sustainable commuting Conclusion The BMS is also used for verifying options for employees. Underground Manitoba Hydro Place successfully and optimizing energy targets and for bicycle storage areas and show- delivered on the goals set out in its observing building performance in ers have made cycling an attrac- project charter. It has led to a new close detail. Several hundred meters tive option for 10% (and growing) wave of development in downtown monitor lighting, plug loads, water of employees in the summer. The Winnipeg, it has achieved new heating, pump and fan energy and building’s carefully selected site levels of sustainability for an office hydronic loads, among others. These is in the hub of Winnipeg’s spoke- tower of its size (expected to be the metering points are a small portion based transit layout, and more than largest LEED Platinum office tower of the more than 25,000 control and 60% of employees take public tran- in Canada [pending]) and reduced observation points in the BMS. sit to work. energy consumption by more than The creation of a supportive, inspir- 60%. In the end, however, the qual- Human Factor ing and healthy workplace ultimately ity of space is the building’s pri- Creating a supportive workplace eclipses energy and productivity by mary achievement. • for employees was always the pri- valuing community and civic pride. mary goal of Manitoba Hydro Place. ABOUT THE AUTHORS Personal control and natural light were City Building and Community large factors in the increased percep- The building form, orientation and Bruce Kuwabara is a partner, John tion of comfort. massing capitalize on Winnipeg’s Peterson and Kael Opie are associates, and Amanda Sebris is marketing direc- At Manitoba Hydro Place every extreme climate energy potential while tor at KPMB Architects in Toronto. employee has access to outdoor simultaneously creating a new pub- Thomas Auer is director at Transsolar in views and receives natural light for lic destination for the city. The solar Stuttgart, Germany. 80% of normal office hours. They chimney marks the main entrance at Glen Klym is an associate at Smith Carter are able to control exterior blinds, the north and a large canopy at the Architects and Engineers in Winnipeg. Tom Akerstream was the energy and and dim light fixtures from their south mitigates gusting winds. The sit- sustainability advisor for the Manitoba computer, and have access to oper- ing of the south end of the building on Hydro Place project. He is currently ate windows for comfort control. a 21° angle to face due south resulted manager of corporate facilities at Manitoba Hydro. Excellent indoor air quality is in an open space for a new public Mark Pauls was part of the internal another feature. Carbon dioxide park. Inside, the public galleria serves commissioning team for Manitoba Hydro is monitored at multiple locations as both a sheltered pedestrian route Place and is currently the building’s on every floor, and typically peaks through the block and an indoor event/ energy management engineer. gathering space.

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