Rendering of rooftop terrace at the Stack in Vancouver.Oxford Properties
As Canada battles climate change, a new Vancouver office building seeks to stack up some early victories.
The Stack is the first new commercial high-rise tower in Canada to be recognized officially as a net-zero emitter of greenhouse-gas-causing carbon from day one of its opening.
Although many buildings across the country are currently being retrofitted to bring their net emissions down to zero, the Stack was first to be built from scratch and meet standards set by the Canada Green Building Council (CAGBC) for design and operational performance.
The developer, Oxford Properties Group, hopes the Stack will set the pace for large-scale carbon neutral construction across Canada. “We’ve learned a lot and we’re already applying what we’ve learned to other projects,” says Andrew O’Neil, the company’s vice-president of development.
The Stack is one of the largest commercial buildings in Vancouver at 37 storeys.Oxford Properties
Oxford’s new net-zero projects include the Hub, a 57-storey, 1.5-million square-foot tower set to open at 30 Bay St. in Toronto in 2025.
Unlike some other leading-edge new green buildings, which are smaller scale or prototypes, the Stack is a full-fledged office tower, one of the largest commercial buildings in Vancouver at 37 storeys and with 555,000 square feet of space. It achieved full occupancy in the fourth quarter of 2022.
There’s both a commercial imperative and a public urgency to building green, zero-carbon commercial projects, Mr. O’Neil says. On the commercial side, it’s a plus to be able to market office space that’s attractive, comfortable and environmentally friendly, particularly as workers are ambivalent about coming back to the workplace since the pandemic.
A study of U.S. workers conducted last year by Essity, a global hygiene and health company, found nearly six out of 10 office workers think their workplaces should be more sustainable.
“People are looking for good reasons to come to the office, and we think we’re offering that with buildings like the Stack,” says Ted Mildon, vice-president of office leasing and operations at Oxford Properties.
“There’s a market for these types of buildings,” agrees Thomas Mueller, founding director, president and chief executive officer of the Canada Green Building Council. “Commercial tenants want them because they fit in with their companies’ own ESG [environment, sustainability and governance] targets.”
In 2015, Oxford, which is owned by the Ontario Municipal Employees Retirement System (OMERS), the public service employees’ huge defined benefit pension plan with more than $124-billion in net assets, set a goal to reduce its carbon footprint 30 per cent by 2025; it’s ahead of schedule, having reduced it by 37 per cent two years ago.
“Tall buildings generally have a lower ratio of roof area to building area, limiting the opportunity for on-site renewables such as rooftop solar power.
— Andrew O’Neil, vice-president of development, Oxford Properties Group
Net-zero buildings can have lower heating, cooling and lighting costs and also help lessen tenants’ carbon footprints as well as the landlord’s, Mr. Mueller adds. “It takes a long time to plan and build these bigger projects, but if they get it right, the building will deliver zero carbon for years,” he says.
It’s not simple to make a tall building like the Stack net zero, Mr. O’Neil says. The project, designed by James Cheng, founder of James KM Cheng Architects, is a twisty array of four glass boxes resting on top of each other.
“Tall buildings generally have a lower ratio of roof area to building area, limiting the opportunity for on-site renewables such as rooftop solar power,” Mr. O’Neil says. The project does have some solar panels, but a lot of its ability to be net zero comes through relying on British Columbia’s primarily low-carbon electricity grid for heating and cooling, he explains.
Ontario and Quebec also have lower carbon grids. Achieving net zero with new buildings in other provinces will be trickier, Mr. O’Neil says.
The Stack’s glass boxes are oriented to get maximum sun exposure to save on heating and lighting, and the glass is triple glazed to save energy. The building also includes small energy-saving features to help it reach net zero, such as sensors in the parking area to dim the lights when there’s no one there and heat exchangers to redistribute heat from one part of the building to another.
The other challenge set by the Canada Green Building Council to achieve net-zero status is to reduce the building’s Thermal Energy Demand Intensity (TEDI). The triple glazing helps, and the building has windows on lower floors that open and close, which lets occupants control the temperature the old-fashioned way, by opening the window and not using electricity.
For Vancouver’s climate zone, the Council set a TEDI target score – where the lower your score is, the better – of 30, he says.
“The Stack’s TEDI score was 21, so we improved on the target by around 30 per cent,” Mr. O’Neil says.
Although buildings like the Stack contribute to Canada’s quest to reach net zero, there’s still a long way to go, Mr. Mueller says. The federal government has committed to reducing Canada’s total greenhouse gas emissions to between 40 and 45 per cent of 2005 levels in the next seven years and to reaching net zero by 2050.
Progress remains slow. The building sector is Canada’s third-largest source of carbon emissions and it’s going to take more than a whole stack of new buildings to get to net zero, Mr. Meuller notes.
“Buildings like this are great because they create the building stock of the future, but we also need to retrofit existing buildings. To get to net zero we’ll need to retrofit about 155,000 buildings of more than 30,000 square feet over the next 30 years,” he says.
Rendering of a gym space at the Stack.Oxford Properties
Lining up the financing for both new projects and retrofits has its own challenges, says Kit Milnes, vice-president of sustainability and resilience at KingSett Capital, a private-equity lender that backs such projects.
“On the retrofit side, we need to move faster to decarbonize to reach the 2050 goal,” Mr. Milnes says. “As for new projects, the Canadian Infrastructure Bank [a Crown corporation that lends] has $2.5-billion to pour into deep retrofits, but there’s nothing allocated for deep builds.”
This offers an advantage to companies like Oxford Properties Group, which has had net zero in its sights for years.
“We’ve designed the Stack to still be great in 100 years,” Mr. Mildon says.