Toronto and Region Conservation Agency Offices Aim For Net Zero Carbon

The Toronto and Region Conservation Authority (TRCA) was "created to safeguard and enhance the health and well-being of watershed communities through the protection and restoration of the natural environment." Its new headquarters building is supposed to be good for the environment too, "applying best practices in green building and sustainable design."

Designed by ZAS Architects in a joint venture with the Irish firm Bucholz McEvoy Architects, it's built out of cross-laminated timber (CLT) made by Element5 in its new factory that just opened down the road in St. Thomas, Ontario, using FSC Certified Ontario wood.

It's going for a whole alphabet of green certifications, from LEED Platinum to WELL Silver to Tier 2 of the Toronto Green Standard and the CaGBC Zero Carbon Building Standard. According to the architects, "This project makes a conscious effort to achieve a smaller footprint through all lifecycle phases, with model simulations predicting over 50% reduction in operating emissions, and over 75% reduction in embodied carbon compared to the average Toronto building."

Project architect Peter Duckworth Pilkington tells Treehugger that it isn't just the CLT. "We really wanted a plant-based building from the slab up- mass timber structure, wood cladding, wood interior finishes," says Pilkington.

Pilkington tells Treehugger the TRCA is "a remarkable organization, with its boundaries set by the watershed." This is a feature the former Toronto mayor David Crombie used to say should have been the political boundaries, the natural division covering all the lands draining down to the lake. Pilkington says it inspired the building, "the ecological premise is based on the watershed." The board room overlooks the Black Creek and conservation area on one side. (Don't look in the other direction—it is a tennis center and giant parking lots.)

The building has natural ventilation to the extent you can do in Toronto, with its very cold winters and hot humid summers, and one problem with that is control. While there are automated systems like blinds, the building occupants are going to be part of the system too. "Under the right exterior conditions, staff will be alerted by the building’s automation system through their personal devices to either open or close windows, to ensure the building is using energy most efficiently," says Pilkington.

But Pilkington notes that "in our climate, we are not there yet in terms of comfort, so where we have active systems, we are making them visible instead of making them disappear." That's why there are four of what are described as "solar chimneys" with "waterwalls" inside. He explains: "[These are] giant glass air ducts with MERV 13 filters on the top. Inside, there are steel mesh screens with water running down, filtered through reverse osmosis and UV, tempered by the ground source heat pumps to be warm in winter, cool in summer."

They worked with mechanical engineers Integral Group and Transsolar, the world-leading engineering firm, on the fluid dynamics of the system. The air is then distributed through a raised floor plenum.

What is a Zero Carbon Building?

The building is certified under the CaGBC Zero Carbon Building (ZCB) Standard, which is one of the first to focus on carbon; we have lots of energy these days, while our current problem is greenhouse gas emissions. CaGBC notes that "the Standard’s focus on carbon pollution is crucial, as the most important factor in the carbon footprint of a building is often not its energy efficiency, but its choice of energy sources."

Its definition:

"A zero-carbon building is a highly energy-efficient building that produces onsite, or procures, carbon-free renewable energy or high-quality carbon offsets to offset the annual carbon emissions associated with building materials and operations."

Treehugger has noted there are two kinds of carbon to worry about in buildings, those that come from the operating emissions, and from the embodied carbon, or upfront carbon emissions.

The Net Zero Carbon claim for the building comes from its certification under the CaGBC Zero Carbon Building (ZCB) Standard Version 1, which I noted earlier "sorta kind of does recognize embodied carbon and someday might even do something about it." Applicants had to measure it but didn't have to actually do anything with it, just report it "to encourage the building industry to grow capacity for conducting Life Cycle Analyses—a practice that is still relatively new in Canada."

The new Version 2 is a lot tougher, but Pilkington defended the use of Version 1, noting embodied carbon was always top of mind and the reason they designed the building to be "plant-based from the slab up."

So while we do not have the math to show that it is truly a net zero carbon building, including both operating and embodied Carbon, it's going to be pretty close. And it is, under any standard, probably the greenest building in the Toronto region.