Toronto’s First Net-Zero Child Care Centre: A Milestone, and a Call to Action
The City of Toronto recently made history by opening its very first new-built net-zero building, and it's not just another green building — it’s a public, community-centered space: the Mount Dennis Early Learning and Child Care Centre.
That’s a big deal.
Here’s why this matters — and why we're proud at Sustainable that our co-founder, Paul Dowsett, played a role in shaping the conversation around it.
What Makes the Mount Dennis Centre So Special
Located at 1234 Weston Road, this 19,000-square-foot facility provides care for 98 children, and even more impressively, it's newly built with no reliance on natural (methane) gas — fully electrified, with energy-efficient systems that set a new standard.
Some of its standout features include:
Super-insulated walls and roof to cut down on heat loss and gain.
Triple-glazed windows, which help with thermal performance.
Airtight construction to minimize air leaks.
Geothermal heat pumps to draw on underground temperature for heating and cooling.
264 solar panels — these generate electricity, preheat hot water, and feed back into the building’s systems.
Energy recovery ventilators, which improve indoor air quality while managing energy flows.
In short, it’s a childcare centre and a powerful example: buildings can protect our children and the climate.
Why This Matters in the Bigger Picture
Buildings are huge contributors to emissions — in the Greater Toronto and Hamilton Area (GTHA), 45% of greenhouse gas emissions come from buildings, according to The Atmospheric Fund.
What’s more, emissions from buildings actually rose in 2024. That makes this net-zero centre not just symbolic, but strategically essential.
Paul Dowsett’s Take — And Why It Resonates for Sustainable
Paul, Principal Architect at Sustainable, spoke with NOW Toronto about why this project is a breakthrough:
“Hats off to the City of Toronto … Hats off to our fellow architects at Cool Earth … We need to advertise this building … make people understand that this is something that can be done.”
His point underscores a belief that’s central to us: net-zero buildings can’t be niche — they should become the norm. They’re not just about energy savings, but also about reducing operational carbon (emissions from running the building) as well as upfront embodied carbon (associated with the materials and construction).
Paul also highlights a critical challenge: most of Toronto’s buildings already exist — about 85% of the buildings that will still be around in 2040 are standing today. That means retrofitting existing buildings to net-zero is not optional; it’s mission-critical.
The Urgency: Retrofitting Is the Key
While celebrating new-built net-zero projects is important, Paul (and other experts) make it clear: we can’t neglect the buildings we already have.
Yes, it is far easier (and more effective) to embed sustainability at the construction phase than to retrofit later — especially when you factor in embodied carbon. Nevertheless, for existing buildings, there are powerful levers:
Replacing gas boilers and furnaces with all-electric cold-climate heat pumps.
Adding air-tightness and insulation.
Sealing up leaky windows.
Making use of energy-efficient tech and controls.
What This Means for Toronto — and for Sustainable
Leadership by Example: The Mount Dennis centre shows that net-zero is feasible, even for publicly funded, community-centered buildings.
Scaling Potential: With this model, city leaders, developers, and communities have a powerful template.
Retrofitting Push: To hit climate goals (Toronto’s “TransformTO” strategy aims for net zero by 2040), we must accelerate retrofits to get all buildings there.
Public Engagement: This building is a powerful storytelling tool — showing Torontonians (and potentially other cities) that sustainability isn’t just “green design,” it’s tangible infrastructure that supports people and the planet.
At Sustainable, We Believe…
This moment is more than a milestone. It’s a turning point.
We see buildings as climate actors — not just places where people live, play, learn, and work, but as systems that shape our carbon future.
We believe in sharing knowledge, showing what works, and making the case for broader adoption.
We’re deeply committed to bridging the gap between new-built construction and retrofits — because both are essential to meeting our climate goals.
