The dramatically slanted roof and sides of the new Toronto Paramedic Services Multifunction Station will be an eye-catcher. Less evident, but equally important, are that its walls and garage doors are designed to conserve heat and the photovoltaic arrays on the roof can produce much of the building’s electrical needs.
Meanwhile, the new Ottawa Public Library and Archives of Canada Joint Facility is weaving photovoltaic elements into its walls and windows to produce significant amounts of electricity. And in Winnipeg, the Red River College Innovation Centre is pushing the envelope with walls clad in colourful photovoltaic glass.
Each of them could have been built with conventional glass curtain walls and standard insulation, but they’re part of a trend that’s seeing architects look for ways to turn roofs, walls and windows into power-producing elements of buildings while maximizing energy conservation.
“Energy-generating architectural materials have been around for a quite a while but not used in significant ways in buildings until now. They’re becoming more efficient and cost-effective for use in large-scale architecture and government mandates are spurring innovation,” says Michael Leckman, principal of Diamond Schmitt Architects.
The City of Toronto mandates that newly commissioned projects achieve zero emissions in the designs as well as investigate net zero energy, which can lead to unique innovations, he notes. “The TPS station is an unusual building to be pursuing net zero energy; three-quarters of the space is used for vehicle maintenance and, owing to strict guidelines around air quality, require immense volumes of fresh air. The most significant use of energy is the preheating of that fresh air during the winter.”
The building, designed by Diamond Schmitt in association with gh3 Architects, is due to start construction in 2022 and will be clad with an innovative solar wall.
“Basically, it is a dark-coloured perforated metal that has a cavity behind it. The dark skin warms up in the sun and the perforations allow the warm air into the cavity but not let it come out again, Mr. Leckman says.
Doubling up on insulation is another key to conserving heat.
“Where previously the standards were R-20 for walls and R-30 for the roof, our walls will be R-35 and roofs, R-50. Once you get to those levels of insulation, the building will see only minor temperature changes when the temperature outside falls, says John McKenna, associate and strategy director of gh3 Architects.
The solar wall and insulation will reduce heating needs by 15 per cent, but another significant saving will come from a vestibule door system.
“This building has nine garage doors and opening them can be a tremendous heat loss in the winter,” Mr. McKenna says. “By adding a second set of inner doors that doesn’t open until the outer doors close, we can save another 15 per cent of the heat. So that’s a 30-per-cent savings just from the design and materials before we start talking about the mechanical systems.”
The internet is a new world of research and as such, the initial inspiration for innovative wall design at Red River College was a tweet about a material developed by a group in Switzerland that turned into a product adopted by SolarLab, a group in Denmark.
Diamond Schmitt principal Sydney Browne travelled to Copenhagen in the summer of 2018 to see the SolarLab PV system in person.
“It was the first step in a three-year process of convincing ourselves, then the College, and then City building and utility authorities that this was worth pursuing,” she says.
There were multiple steps in testing and approvals, and choices of colours and appearance compatible with neighbouring turn-of-the-century brick warehouses.
“It needed to be thought through, because it was being done this way for the first time. As the components for this type of system become more readily available and affordable, I am extremely hopeful that this technology will become more commonly used. We really are on the cusp,” says Ms. Browne, who has been invited to present on the experience to the National Research Council this fall.
The Red River College Innovation Centre, built in a joint venture with Number TEN Architectural Group, is nearing completion.
“We are covering the south and west and part of the east walls of the upper three floors of the building, it’s about 50 per cent of the total surface area of the building,” Mr. Leckman adds.
“Each glass panel is three millimetres thick with photovoltaics adhered to the back; it arrives prefabricated and attached to frames that you can hang onto the building like pictures. When connected to inverters they create electricity,” he says. “A remarkable thing about this material is that it conceals the PV cells, and instead comes in a range of dynamic colours that change depending on your point of view.”
In Ottawa at the OPL-LAC Joint Facility, photovoltaic elements are being arrayed on stone walls of a building that connects a federal and municipal institution under one roof for the first time, linking their dedicated spaces with an expansive public forum that offers visitors a wide range of meeting spaces, technical resources and improved energy efficiency.
“We started with LEED Gold certification in mind, so smart, energy-efficient design was part of the design from the beginning. A district energy source is going to deliver carbon-neutral or low-carbon energy and with that already in place, the next step was to aim to make the building carbon-neutral and create features that are energy sources,” says Gary McCluskie, principal at Diamond Schmitt, which took on the $181.1-million project in joint venture with Ottawa-based KWC Architects.
Photovoltaics can be integrated in ways that reinforce the character of the architecture, he says. The façade is built of heavy stone in a variety of colours and on the south side, the walls are intertwined with integrated photovoltaic panels.
“We did a lot of studies to ensure that the colours of the stone and the photovoltaic panels are compatible, but also identifiable.”
All of the windows in the building are triple-glazed in order to increase the R-value of the building.
“We made the glass as well as the insulation behind the stone panels R-30 and the roof R-40.” Mr. McCluskie says. Other features include a green roof and a green wall inside the building.
For the reading rooms and the book stacks, natural light is important, so within the stone section of the building near these areas, there are horizontal window sections that include integrated photovoltaics. “Basically, the photovoltaics are glued to the back of the glass and even though visibility is reduced, light still passes through it. It’s like a heavy tinting on the glass and it generates electricity,” he says.
“These are all materials that are available in the construction industry; they are quickly emerging and will develop more as incentives to go carbon-neutral expand,” Mr. McCluskie says. “I would suggest that wall-installed photovoltaics are going to be something that every building in the future will look to experiment with.”