A Lifecycle Assessment-Based Environmental Analysis of Building Operationally Energy Efficient Houses in Nova Scotia

Abstract

In contribution to Nova Scotia’s energy goals, incentives have been developed by the province’s energy efficiency utility to encourage homeowners to increase their home’s efficiency. Although operational energy efficiency in homes has been well-studied, few studies use a lifecycle approach to analyzing the environmental impacts of single-family dwellings from material extraction through to disposal. This project uses life cycle assessment (LCA) methodology and operational energy modelling to analyze five single-family dwellings in Nova Scotia with the same footprint but varying operational energy efficiencies. Through this modelling, the environmental impacts of each home can be analyzed and compared in terms of life-cycle stages and materials. The results of this study show that the largest environmental impact savings come from operational energy upgrades. The most efficient home in this project, the Net Zero home which produces electricity using PV modules, has on average 96% lower environmental impacts than the project’s baseline home among all nine environmental impact groups. However, when considering only the embodied impacts (all life cycle stages excluding operational), the Net Zero home has 11% higher embodied impacts than the baseline home. Although embodied impacts increase as NS homes are built more efficiently, the impacts are minor compared to the saved impact created by decreasing the home’s operational energy.