Exceeding the Ontario Building Code for low-rise residential buildings: Economic and environmental implications

• Four homes were modeled to compare annual energy use and related carbon emissions.
• One home just met minimum code requirements, while the other 3 had energy efficiency upgrades.
• Financial viability of the upgraded models was highly dependent on future utility prices.
• More energy efficient measures were found to have higher carbon abatement costs.
• Policy recommendations are provided to more appropriately value low-energy housing.

The residential sector accounts for approximately one fifth of Canada's secondary energy use and greenhouse gas emissions. Thus, addressing the energy efficiency of residential buildings has a significant role to play in reducing the nation's overall greenhouse gas emissions. The Ontario Building Code has recently been updated to reflect a more stringent energy performance standard. A home built to the prescribed minimum requirements will perform at a relatively high standard with respect to energy use when compared to homes built less than a decade ago. This paper explores three energy efficiency upgrade options which improve upon the energy efficiency of the 2012 Ontario Building Code. The “controlled ventilation” upgrade involved tightening up the building envelope and adding heat recovery to waste air streams, and two additional upgrade options were developed to meet the high performance targets of the R-2000 standard. While the upgrades explored did not show financial benefit for individual homeowners at current utility rates, if the benefits to society are considered, the upgrades are an economically efficient method of reducing greenhouse gas emissions owed to energy consumption. In addition to highlighting the need for a broader approach to the cost-benefit analyses associated with these types of upgrades, this finding also warrants a discussion about how to transform the current housing market so that energy efficient homes are more appropriately valued.