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A Green Signature for Manitoba Hydro Climate and Collaboration Shape Innovative Building
April, 2007
By Barbara Carss
Plans for Manitoba Hydro's new corporate headquarters began with a contractual obligation, but were perceived as an opportunity to deliver a high-performance building that could provide productive workspace for the provincial Crown corporation's 1,800 employees and support revitalization efforts in downtown Winnipeg. The 22-storey, 690,000-square-foot tower now under construction on the south side of Portage Avenue has been designed to achieve LEED (Leadership in Energy and Environmental Design) Gold status and 60% greater energy efficiency than the standards set in Canada's model national energy code for buildings (MNECB).
"That is about double the savings that other office buildings have attained," notes Luigi LaRocca of Kuwabara Payne McKenna Blumberg Architects (KPMB). His firm is the design architect and a key player in the integrated design process that underlies Manitoba Hydro's approach to the project.
"How you develop means as much as what you put into the building," asserts Tom Gouldsborough, Divisional Manager, Corporate Planning & Business Development, with Manitoba Hydro and the project manager for its new head office, which is scheduled for completion in May 2008. In this case, the development is grounded on five guiding principles that set out goals for the building's ecological footprint, its role in Manitoba Hydro's long-term business plans, impact on downtown vitality and relationship to the surrounding streetscape.
INTEGRATED DESIGN PROCESS
Particular emphasis was placed on choosing the project site and design team. This included the largely unprecedented step of issuing separate requests for proposals (RFPs) for each of the design disciplines involved, along with a requirement to work collaboratively in an integrated design team.
As recently as 2002 - when Manitoba Hydro acquired the assets of the former municipally owned Winnipeg Hydro and pledged to build a new head office downtown as part of the purchase agreement - this was still very much uncharted territory. Examples of LEED certified buildings and/or comparable energy efficiency and sustainability standards were still quite rare at the time, but proponents saw potential in the process.
"The integrated design process is the methodology that makes sustainability work," says Dudley Thompson, Principal with Prairie Architects Inc., the Winnipeg-based firm that served as Manitoba Hydro's advocate architect to oversee the site selection, advise on the hiring of the design team, and facilitate the collaborative design process.
The Hydro headquarters evolved through a series of 10 intensive work sessions in which designers would gather for two days of brainstorming, then return to their offices to refine their own components of the plan before meeting again. "There were sometimes 40 consultants at one meeting sitting around the table," Thompson recalls. "We did a lot of decision making in those two-day sessions."
Cost consultants were also an important part of the team. When the designers proposed higher ceilings and a narrower floor plate to allow for greater penetration of natural light, for example, consultants helped the decision makers weigh the capital cost implications against the probable outcomes.
"Our development team told us: every inch of height is another 50 cents per square foot," Gouldsborough says. "But we think that 80 to 85% of the time you won't see lights on in this building."
Gouldsborough, LaRocca and Thompson all credit the energy/climatic engineering firm, Transsolar Energietecknik of Stuttgart, Germany, with providing critical guidance on how best to capitalize on Winnipeg's abundant sunlight and respond to its dramatic range in temperature from winter to summer. This called for a design that would maximize solar exposure at the south facing façade and reduce thermal loss through the north side of the building.
COMPLEMENTARY CONCEPTS
The result is a fully glazed structure with two sections that present a narrow frontage to the north, and angle out in two directions to create a broader southern façade. "The east and west towers open up like a book from the north pivot point," Gouldsborough explains. A stack of three six-storey atria link the building together at both its north and south ends and are the basis of the building's innovative ventilation system, which supplies the office space with 100% fresh outdoor air, all day, year round.
"We didn't show up with a preconceived notion. We worked with everybody, especially Transsolar, to discover: what does it mean to take a building to another level of energy efficiency?" LaRocca says. "The form of the building really came out of the process."
Notably, the engineers devised the atria as a configuration for solar collectors, air exchangers, air handlers and airshafts. Fresh air enters through the south atria, travels upward via raised floors and is exhausted out a solar chimney on the north side of the building.
During cold weather months, when temperatures in Winnipeg can plunge to the -40( C range factoring in the wind chill, the solar collectors in the atria will warm the incoming outdoor air and counter thermal heat loss. Exhaust air from the solar chimney will also be used to pre-heat incoming air through a heat exchanger, and to heat the 150-space parkade.
For their part, the architects saw an opportunity to create "vertical neighbourhoods" using the atria as a focus for the column-free office space arranged around them, and incorporating staircases to forge a better vertical connection between the floors of each six-storey section of the building.
The atria are also a distinctive architectural feature, particularly on the building's expansive south side, allowing passersby to easily see inside. A large-scale water feature slated for the south atrium will serve double duty as public art and a humidification/dehumidification mechanism.
"The notion of having a six-storey atrium is, on a really base level, a kind of mechanical optimization," LaRocca observes. "We found there was a way to take these ideas and give them shape and get a good urban building. The building really took shape that way, and it wasn't a compromise. It was a collaboration that made something better."
Other notable features include: geothermal heating and cooling; a green roof; exposed radiant concrete ceilings; and an unique building envelope with a double façade so that the outer skin provides a buffer against extreme outdoor temperatures, while the interior shell allows for operable windows.
COSTS AND OUTCOMES
Rising construction and material costs and some unforeseen complications have thus far inflated the project budget by $20 million over pre-construction estimates announced in 2005. However, number crunchers also project that the capital investment, now at $278 million, will yield approximately $15 million in annual operating cost savings - $7 million of which reflects the leasing costs of space Manitoba Hydro will give up when it consolidates staff in the new downtown location.
Other economic benefits are anticipated, but more difficult to gauge. Simply housing all personnel in one building should support their ability to work together more efficiently and effectively, but Gouldsborough foresees additional productivity spinoffs in a working environment that offers more fresh air, more natural light and more control over the space, such as the flexibility to open windows.
City of Winnipeg officials also look forward to the spinoffs of gaining up to 2,100 potential customers - who will be working for Manitoba Hydro and in other office and retail space in the building - for downtown businesses, downtown transit routes and potential downtown residential development. Planning and economic development strategists are particularly pleased to see investment on the south side of Portage Avenue to complement new development that has recently occurred on the north side. "The City has been working hard to balance that out," says Winnipeg Councillor Russ Wyatt, who chairs the City's standing policy committee on downtown development.
FITTING INTO THE DOWNTOWN DYNAMIC
The downtown location was part of Manitoba Hydro's purchase agreement for Winnipeg Hydro, and entailed some important decisions about the setting and scale of the project. Several criteria were employed in choosing a site that would best support sustainability, provide convenient access to parking, transit and services, and provide some prominence in the streetscape and skyline.
At street level, the three-storey podium is clad in Manitoba Tyndall stone. Along with the formal main entrance on Portage Avenue, there is retail space opening onto Portage Avenue, Edmonton and Carlton Streets, and a landscaped public courtyard and park at the south entrance along Graham Avenue. The building also connects on the second level to Winnipeg's elevated downtown pedestrian walkway system. "We are creating wider sidewalks than are found in Winnipeg so we are consciously trying to set a new urban standard," LaRocca adds.
Approximately 32,000 square feet of office space will be available for lease, but Hydro officials rejected proposals to build something significantly larger than the corporation's current needs and lease the excess commercial space since that could cause a glut in the downtown office market. "We had to be really conscious of the unintended consequences of it all," Gouldsborough says.
This effort to consider impacts and balance perspectives comes through in the final design. "I think initially Hydro might have wanted the tallest building in the city, but as the design evolved, sustainability took hold and practicality predominated," Thompson reflects. "It's a very graceful and beautiful building. From the south, particularly, it's going to be spectacular, but it was never conceived as a monument."
Word of the building's sustainability achievement is already spreading widely, and that, Gouldsborough reasons, could be the best way for architecture to denote and celebrate its setting. "Part of the signature of the building is the energy efficiency and the fact that it is responding to this climate," he says. "It was designed for Manitoba."
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