CNERG: Charting a path to net zero homes through optimized retrofits

Single-detached homes account for more than half of Canada’s residential buildings and consume more than twice the energy per capita compared to apartments. To help meet Canada’s 2030 and 2050 emissions reduction targets, this research focused on identifying the most effective retrofit strategies to reduce energy use in these homes, using a case study modelled on a house in Cambridge, Ontario. 

Through building energy modelling and a sequential search optimization method, the study evaluated combinations of retrofits including insulation upgrades, air leakage reduction, high-efficiency HVAC systems, and LED lighting. The optimized plan reduced the home’s energy use intensity by 80 per cent. Installing solar photovoltaic panels on two-thirds of the roof’s south-facing side brought the home to net zero energy use, with the potential to generate surplus electricity. 

By identifying both optimal and near-optimal retrofit combinations, the research offers homeowners flexibility in how they pursue energy upgrades. The findings also provide practical guidance for designers, contractors, and policymakers working to scale retrofits for existing single-family homes in similar Canadian climates.