An energy retrofit roadmap to net-zero energy and carbon footprint for single-family houses in Canada

Building decarbonization initiatives have gained momentum in recent years as many cities and governments are establishing net-zero emission tar-gets. Although many municipalities have already introduced energy requirements and metrics to promote new high performing and net zero con-structions, decarbonization of existing residential buildings suffers from a lack of a clear roadmap. This study establishes a comprehensive roadmap for decarbonization and electrification of typical existing single-family houses in Canada in two different climate zones. A typical single-family dwelling-with two floors and a basement was energetically modeled and the results were validated versus utility bills. Afterwards, a range of energy conservation scenarios and measures were applied to the case study building using an individual and cumulative approach, with an analysis of the energy use and carbon footprint reductions. The results indicated that when a phased approach for the retrofits is considered, an approximate invest-ment of 40,000 CAD could result in 78% energy saving and 96% emissions reduction in an existing residential building in Ontario. For Vancouver, the energy and emission savings are reported as 85% and 100%. The results were further investigated using a sensitivity analysis considering future scenarios for grid emissions and carbon costs. Finally, an embodied carbon inventory analysis was conducted showing that, in particular, the positive impacts of adding exterior wall insulation dominantly sways the negative impact of its carbon footprint from material production. The study con-cludes by highlighting the key findings and presenting a number of avenues for future research.

Automated summary

This study establishes a comprehensive roadmap for decarbonization and electrification of typical existing single-family houses in two different climate zones in Canada, showing that significant energy and emission savings can be achieved through phased retrofits.