The sustainable design approach is founded on a series of strategic decisions relating to site selection, building placement, orientation and massing, which support the goals of flexibility, energy efficiency, human comfort and superior indoor environmental quality.
The project features a building technology platform (raised floor system) for the supply of cooling and fresh air. It contains all voice, data and power distribution cabling. Supply air is delivered via the pressurized under-floor plenum through manually adjustable diffusers, allowing for individual control of air quantity and temperature. Automated diffusers are used within enclosed spaces as well as providing additional cooling at the perimeter to address solar load fluctuation. The supply air is 65º to 68°F on average, rather than the typical 54º to 56°F temperature used in an overhead system. This allows for greater access to free cooling and is much more comfortable. The perimeter heating (exterior zone) is provided by an in-floor, hot water fin-tube convection system which creates a warm air curtain at the glass.
Daylight is harvested effectively using external sunshades and interior light shelves placed below the slab. The light shelf and blinds are fully automated. Working with the building’s orientation (long sides facing due south), this system minimizes glare while providing natural light penetration deep into the building. As sufficient natural light is detected, the perimeter artificial lights are turned off.
The structure is poured-in-place, reinforced concrete which is exposed throughout. The atrium roof structure features lightweight king post steel trusses and a butterfly design to allow natural light penetration through clerestory windows while minimizing glare and solar heat gain. Indoor environmental quality was extremely important to the client. The naturally stratifying, occupant-controlled supply air ensures effective fresh air delivery. The building also uses low-VOC emitting materials.
Flexibility in planning was seen as a way to increase the service life of the building by facilitating future reconfiguration or change of use. Crucial to reducing the cost of future change is the selection of systems that facilitate these changes. In the Loblaw headquarters building, this includes the continuous pressurized plenum for air distribution, structured data network connectivity, and modular convenience power. The consolidation of services (except sprinklers and lighting) below the floor leaves a 3.25m high interior space that is easily adapted to a multitude of uses.
Externally, the site design strategy includes a number of features and design approaches that enhance the environment and support natural ecosystems. Storm water is collected and retained in a naturalized retention pond that serves the needs of the Loblaw building and other buildings in the vicinity. This communal pond retains and filters stormwater, providing a large, naturalized habitat for local birds and wildlife.