Life Cycle Assessment for Modular Roof Systems of Large-Span Building

Material extraction, production, transportation, construction, operation, and maintenance consume huge amounts of energy that contribute to environmental pollution and contribute to climate change. In 2017, the building sector was found to be responsible for 39% of energy consumption and associated greenhouse gas (GHG) emissions [1]. In Canada, the industry and building sectors are the highest contributors to total energy consumption. Hence, the embodied and operating energy and their associated GHGs in the building materials, and the operational primary energy over the whole life cycle of buildings, must be assessed [2]. This paper thus presents a Life Cycle Assessment (LCA) approach to evaluating the environmental impact of different modular roof systems, including precast hollow-core concrete, composite roof system, steel roof system, and wood roof system. A case study of a large-span industrial building in Calgary, Alberta, is selected and then analyzed to assess the associated environmental impact of different alternatives of roof systems at each stage in the life-cycle. GHGs and environmental impact parameters and metrics such as embodied and operating energy, fossil fuel consumption, global warming potential, ozone depletion, air, land, and water emissions, and smog potential are analyzed using ATHENA^® impact estimator. Wood and steel roof systems are shown to have the lowest energy consumption and lowest GHG emissions.