Page E2.2 . 24 April 2002                     
ArchitectureWeek - Environment Department
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    Cool and Green


    Despite these amenities, the Computer Science Building was built for the $168 Canadian per square foot ($C1808 per square meter) cost proposed in the development budget. This contrasts with most green buildings, which tend to cost more than originally projected.

    A Dynamic Response to Climate

    Although it is too early to demonstrate whether the design will ultimately achieve the projected 50 percent savings in overall energy consumption compared to a standard building of the same size, there are encouraging signs.

    Architects Alliance describes the building as "highly insulated for a cold climate, capitalizing on solar gain and heat absorption in an exposed structure" while performing at other times of the year as a "naturally ventilated tropical structure."

    This is because Toronto experiences large seasonal temperature swings, with winters typically hovering around freezing, summers often reaching the 90s Fahrenheit (30s Centigrade) with high humidity, and spring and fall weather that fluctuates between both extremes.

    Natural ventilation induced by thermal chimneys on the roof, a central atrium that stratifies heat, and a large amount of operable perimeter glazing gives the building "free" cooling on warm days in the spring and fall and nighttime flushing in the summer. Air circulates freely from space to space, through simple air transfer grills in bulkheads over doors, moving from classrooms to corridors to large atria.

    The architects couldn't escape a high energy demand to deliver uninterrupted, heavy-duty cooling to counteract computer-generated heat. But they allowed nature to temper this demand by strategically locating the computer labs on the coolest, northern side of the building.

    According to Walter Bettio, an Architects Alliance associate and project director for the Computer Science Building, the architects took a holistic environmental approach, considering more than energy efficiency in its design.

    He says: "We chose elements requiring very low energy to produce, and which were low in volatile organic compounds. We kept toxic emissions from primers and adhesives down during construction."

    For the concrete, the architects specified fly ash to replace 50 percent of the more typical Portland cement, which requires a great deal of energy to produce and gives off a lot of carbon-dioxide during its manufacture. "By substituting fly ash, a byproduct of burning coal, Bettio explains, "we reduced the amount of greenhouse gases released into the atmosphere during construction, enormously."

    They also reduced electricity consumption for lighting by about half because of ample natural light and the use of indirect, up-and-down, and semidirect electric lighting. Energy output for the building's steam heating system has been about 40 percent lower than for a comparable campus building, although some of that is attributable to an unusually mild first winter.

    Assessing Performance

    While there are no design or engineering breakthroughs in the building, Bettio notes, there are refinements of proven green principles "integrated with more sophisticated building technologies and a reinterpretation of how to move air around and how to orient building programs to take best advantage of the sun's orientation."

    Until the architects produce a specific baseline for the building's energy consumption, they won't be able to make any precise comparisons with the few buildings in Canada that incorporate the same high performance components.

    Guiding the development of that baseline is a computer-based building management system that monitors outdoor wind direction, wind speed, air temperature, and other conditions and relates them to mechanical equipment performance.

    An "intelli-meter" in one of the building's public corridors also tracks and displays various aspects of the building's energy consumption, relative to a sample baseline, and simultaneously displays performance.

    The building was one of three structures representing Canada in the Green Building Challenge symposium in Maastricht, the Netherlands, in October 2000.

    Striving for Higher Standards

    Peter Busby, principal of Busby + Associates Architects which partnered with Architects Alliance on this building, is also Canada's leading proponent of green building design. He notes: "All the buildings being designed in this office follow LEED principles (from the U.S. Green Building Council), although we have varying degrees of success convincing clients to adopt some shade of green as part of their business practice."

    Busby also chairs the broadly-based Sustainable Building Canada Committee, established in January 2001, which actively promotes green building design and implementation, and which is working toward a national baseline modeled after the U.S. LEED standard for sustainability.

    The committee includes public and private sector representatives, architects from across Canada, engineers, building material suppliers, building owners and managers, specification writers, and interested others.

    Busby counts among the committee's accomplishments thus far the development of a one-day course in sustainable design fundamentals, which some 15 percent of Canadian architects had taken by mid-March, 2002. More courses are in development.

    Besides education, Busby says, another priority for the committee is adoption of a national assessment tool. They searched in Canada and other countries and concluded the appropriate regulatory and certification tool is LEED.

    Busby says: "We're putting together an implementation strategy which will be focused on a new nonprofit Canadian Building Council, probably based in Ottawa, to promote green building more actively and certify LEED projects across the country."

    That LEED model, he added, will be modified for Canada, and further refined with LEED-type documents in several zones across the country. The Province of British Columbia has already written and implemented its own LEED document.

    Busby says that, until about two years ago, Canada was ahead of the United States in green building design. "The LEED tool has spread like wildfire across the United States, so better buildings, even average U.S. buildings, are being built under LEED, and they too are better than average Canadian buildings.

    "The United States has raised the bar in terms of green building design, and generally follows more progressive strategies than Canada, largely due to the success of LEED," Busby says.

    Does he foresee a time when Canada could regain its lead in sustainable green building design? "Yes, we could one day overtake LEED because we have, for example, a more proactive role towards the Kyoto Protocol and controlling harmful emissions than the Americans," he says. "If we get going we could jump higher than LEED."

    Albert Warson is a Toronto-based freelance writer and editor who covers real estate development and architecture for North American publications.



    ArchWeek Image

    The design of the Computer Science Building is functional, contextually responsive, and unapologetically modern.
    Photo: Steven Evans

    ArchWeek Image

    In a passive air circulation system, outside air is conditioned in an underground plenum and drawn up through floor diffusers into occupied spaces. The central atrium acts as a stack for venting hot air.
    Image: Architects Alliance/ Busby & Associates Architects

    ArchWeek Image

    The building is organized into zones to promote energy efficiency and student-faculty interaction, and to ensure future flexibility.
    Image: Architects Alliance/ Busby & Associates Architects

    ArchWeek Image

    The south facade is extensively glazed, with aluminum sunshades and a glass canopy to provide articulation and protection from the elements.
    Image: Architects Alliance/ Busby & Associates Architects

    ArchWeek Image

    The main atrium is surmounted by a fritted glass roof and motorized clerestory windows controlled by automated wind sensors.
    Photo: Steven Evans

    ArchWeek Image

    The thermal chimneys introduce light into the north-south hallway. As heat accumulates in the chimneys, a stack effect vents heated air from the building.
    Photo: Steven Evans

    ArchWeek Image

    When open, louvers at the rear of the lecture hall flood a typically windowless space with light. Closed, they black out the hall for projected presentations.
    Photo: Steven Evans

    ArchWeek Image

    In the "crush space," a principal meeting place for students and faculty, full-height south-facing windows provide passive heating in winter.
    Photo: Steven Evans


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