Towards sustainabilitiy: Prioritizing retrofit options for Toronto's single-family homes

This study investigates a preliminary retrofit ranking framework for single-family homes on the basis of net environmental effect. Four archetype homes developed to represent Toronto's existing housing stock were modeled using HOT2000 to calculate the operational energy requirements. The embodied effects of selected retrofits were then calculated using the ATHENA Impact estimator and a list of environmental summary measures produced. A method of combining operational and embodied effects based on these eight summary measures was proposed and the functioning and sensitivities of the equation were explored. The method is preliminary and incorporates two factors, a weighting factor and building science factor, that require further research. Analysis of the simulated retrofits allowed generalizations about energy performance and prioritized retrofit recommendations for archetypes. In most retrofit cases operational energy dominates, however, the ranking equation shows the potential for certain conditions in which the embodied effects determine the ranking of a retrofit.