Thermal & Windows

Mixed-use project combines sustainability, transit density and community activation

By Patrick Cotter

This 52-storey, transit-oriented mixed-use project in Surrey, BC features 349 residential suites, a 144-room hotel, a vertical higher education campus, a mixing lobby that serves all building occupants, a rooftop garden, fitness centre and underground parking.

The project can be seen as part of Surrey’s strategic move away from sprawling, automobile dependent low-density strip malls, mega-blocks and single family and medium density housing. In this context, the project adds significant residential, transit-oriented vertical density to the city centre. Adjacent to a transit station, and within 500 metres of a major bus loop, the developer reduced its parking count by reaching an agreement with the City to lease unused parking spaces at the adjacent City Hall.

The design team set out to incorporate the aspirations of the community in the project. In addition to transit-oriented density, this includes sustainability and a varied program to enrich and invigorate community life. The project defines the east side of Civic Plaza, with Surrey City Hall to the north and City Centre Library to the west. The added presence of a restaurant and café flanking the lobby animates the plaza edge, while the combination of residential, hotel and university uses contributes to the flow of pedestrian traffic throughout the day.

For the benefits of this mixed-use program to be realized, 3 Civic Plaza had to achieve more while competing in terms of cost with single-use developments of a similar scale. The key to success was an innovative structure that replaced the usual lateral design solution, based on a single central service core, with an elongated, linear shear wall that stretches nearly the full width of the building, combined with end shear walls that run perpendicular to it.

The advantages of this approach were three-fold:

• A conventional central core structural design represented 33% of the construction budget and the chosen solution reduced those costs by 5% while providing the same strength.

• Vertical circulation in a single central core would have resulted in spatial inefficiencies given the mixed-use program of the building. The chosen solution allowed for individual structural grids and exit stairs for each occupancy.

• The exposed concrete of the 2ft-4.5ft (600mm-1450mm) thick end shear walls also serves as the exterior finish in these locations, reducing overall material use. The anticipated advantages of program flexibility afforded by the reconfiguration of the lateral load resisting system was proven sooner than expected, in fact while the building was still under construction.

The five floors immediately beneath the 38 floors of residential condominiums were originally designed for office use. When circumstances changed, the open floor plate that the structure enabled was easily adapted to the needs of Kwantlen Polytechnic University’s urban business campus.

At a detail level, operable windows, controllable roller blinds, and passive natural ventilation prevent the overheating typically associated with western exposure. Natural ventilation and passive cooling were addressed by simulating a dual-skin façade with a cavity between the window system and heat rejecting roller-blind fabric. The blinds keep solar radiation in the cavity behind the glass; operable window vents at the top and bottom activate a stack effect.

The five floors beneath the 38 floors of condominiums were designed for office use. Balconies are thermally broken from the interior floor slabs with Schöck Isokorb balcony thermal isolators.

Vitro Architectural Glass supplied: clear tempered glazing (4, 5 and 6mm) and clear annealed glazing; 6mm clear tempered fritted glazing (guitar-pick shaped windows seen in photo 1); 6mm clear tempered glazing with Solarban 60 coating (residential and hotel glazing); and 6mm clear tempered glazing with Solarban 70 coating (office glazing).

Patrick Cotter Architect, AIBC, AAA, OAA, SAA, Int’l Assoc. AIA is a partner at ZGF Architects Inc.

PROJECT PERFORMANCE

Energy intensity (building and process energy) = 104.7 KWhr/m²/year
Energy intensity reduction relative to reference building = 34% below BC Hydro Baseline and 50% below Fortis Gas Baseline

PROJECT CREDITS