International Passive House retrofit certification a first for Toronto

Located in Toronto’s Danforth neighbourhood, the Sammon Passive House home has the advantages of a newly-constructed Passive House, including increased comfort, resilience, durability, and energy savings of almost 75-90 per cent of typical homes (Passipedia), but it is a deep retrofit of an existing 80 year old building. 
Existing buildings are Toronto’s “largest source of emissions, accounting for about 55 per cent of total city-wide emissions”. Yet, the deep retrofit of existing buildings also represents an opportunity: building emissions reductions of over 80 per cent are possible if Toronto’s existing building stock undergoes deep retrofits by 2050 (City of Toronto ‘Net Zero Existing Buildings Strategy’ June 2021).  

Passive House design principles used throughout the home include: adding additional insulation to the floor, walls and roof; triple-pane high performance Passive House windows; an air-tight envelope; a ventilation system with heat recovery ensuring hygienic reliable, fresh air while reducing heating costs. Reduction of thermal bridges (highways for heat) as much as possible via careful detailing; waste water heat recovery to pre-heat incoming water from the hot water tank; and, large south facing windows in the main living area and kitchen to harvest sunlight in the winter, while exterior shading helps block the hot summer sun.
Re-using the existing home meant we were able to substantially reduce the embodied carbon emissions for the project: for instance over 80 per cent of the brick walls of the home, and much of the concrete and wood framing were retained.

The Passive House EnerPHit program was created by the Passive House Institute for existing buildings that use Passive House design principles and components. The major difference between Passive House Classic and EnerPHit is due to the difficulty of minimizing all thermal bridges in existing buildings, especially their basements and foundations in a cost-effective manner. 

As most existing buildings in Toronto will undergo renovations and capital upgrades in the next 30 years, there is a great opportunity for home and building owners to seek Passive House EnerPHit certification for deep retrofits.

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