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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, actu- ally 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 Tto 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 the IDP 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. To 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 pub- lic pedestrian throughway. The galleria also © Tom Arban © Tom hosts farmers markets and charity events. 8 HIGH PERFORMING BUILDINGS Fall 2011 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.