Sustainability assessment framework for low rise commercial buildings: life cycle impact index-based approach

The building industry has regularly been criticized for resource exploitation, energy use, waste production, greenhouse gas emissions, and impacts on the landscape. The growing population demands more built environment to accommodate the socioeconomic wellbeing. Adopting conventional construction practices would continue the aforementioned issues. Therefore, it is important to integrate life cycle thinking into building construction to minimize its social, environmental, and economic impacts. The objective of this study is to assess the life cycle impact of commonly used wall-roof systems for low rise commercial building construction in Canada. A framework is developed to assess different building alternatives using the triple bottom line of sustainability. Identified environmental and socioeconomic impact indicators are eventually aggregated to develop a life cycle impact index. Material quantities of six wall-roof combinations for a single-storey commercial building were obtained from industrial partners. State-of-the-art life cycle assessment software is used to assess the life cycle impacts of different wall-roof systems. To accommodate decision makers' preferences of sustainability, wall-roof combinations are assessed for three potential scenarios namely, eco-centric, neutral, and economy-centric using multi-criteria decision analysis. The framework has also been implemented on a case study of low rise building in Calgary (Alberta, Canada) to evaluate its practicality. The study results revealed that the concrete-steel building is the most sustainable alternative in neutral and economy-centric scenario while steel-wood building is the most sustainable building in eco-centric scenario.