Life Cycle Thinking–Based Selection of Building Facades

Abstract

The building industry has a high energy consumption, which results in natural resource depletion, land use, ecosystem degradation, atmospheric pollution, and many other environmental impacts. Therefore, in modern construction, while maintaining a satisfactory and comfortable interior environment, less energy consumption and resource use is a major objective of building design. This research explored life cycle energy (LCE), life cycle assessment (LCA), and life cycle costing (LCC) to evaluate the sustainability performance of building facades for their selection. A research framework was proposed considering environmental, social, and economic impacts (triple bottom line approach). The proposed framework was applied to a medium-rise commercial building in the city of Belo Horizonte, Brazil. Four building facades (brick, granite, aluminum, and glass facades) were selected and compared by their life cycle impacts (i.e., impacts in the preuse, use, and postuse phases). An energy model was developed in DesignBuilder 4.2 to estimate the impact of the energy demand of each facade during the operational phase. LCA of each facade was performed using SimaPro 8 software. Later, selected facades were compared using multicriteria decision analysis for three proposed scenarios: proenvironment, neutral, and proeconomic. Based on the analysis, brick facade was identified as the most sustainable facade in the neutral and proeconomic scenario, whereas a granite facade was the most sustainable alternative in the proenvironment scenario. Life cycle emergy analysis was conducted to validate the proenvironment scenario results. This study provides decision support to architects and engineers for the selection of sustainable building facades based on the triple bottom line of sustainability.