To be the first Net-Zero childcare to operate in Toronto means setting a strong precedent for future childcare centres. Following the criteria outlined by the CaGBC and Toronto’s ambitious framework report, Mount Dennis achieves its Net-Zero standard by using a culmination of different passive design strategies, airtight construction, and an extensive renewable energy system. It is an all-electric building with built in resilience in the form of batteries.

One very simple strategy involves program placement. We located the children’s playrooms to the south of the building to maximize windows and openings on the southern face. This increases solar exposure/gain which improves the conservation of thermal energy on the inside while reducing the dependency on artificial lighting.

Choosing the right materials also has a considerable impact on the building’s embodied carbon: the amount of energy expended in a material’s production, transportation, assembly, use and eventual decommissioning. We chose wood beams and exposed wood ceilings for its low embodied carbon and for the warm characteristics that would fit well for a childcare.

From as early as schematic design, the design process was always informed by valuable numerical data extracted from our Athena Impact Estimator model, a building energy model that creates calculations for thermal bridging. Incorporating this data helped in identifying potential thermal bridges, and improving their construction to mitigate unnecessary heat gain/loss.

The centre is powered by a bed of 324 PV/T solar panels located on the roof, which generate electricity and preheats domestic hot water and recharges the geo-exchange field. This building is able to weather a power outage for 12 hours in the coldest darkest month of the year while maintaining health and safety for its occupants. In addition, the childcare is fashioned with low-flow water closets, dedicated fresh air VAV boxes and high-efficiency enthalpy-wheel based DOAS air handlers to improve energy efficiency.

Although this new childcare is a sustainable building, our intention was not for it to scream “I am green!” but instead, insert itself as a friendly, handsome addition to the neighbourhood and which just so happens to be Net-Zero Carbon.

To find out more about energy-efficient design, take a look at our previous work.