Life cycle integrated analysis of thermal, environmental and cost performance of building envelope system: Small house case study considering grid mix change in Brazil

Abstract

Dwellings with inadequate envelopes tend to present higher energy consumption, consequently, higher energy costs and significant environmental impacts. However, improving performance may increase initial costs. Life Cycle Assessment (LCA) and Life Cycle Cost (LCC) are used to independently evaluate the environmental and cost implications of thermal performance. Thus, it is necessary to help designers synthesize these criteria. This article analyzes the thermal, environmental, and cost performance of a single-family house in Brazil’s coldest climate zone with alternative conventional and innovative construction systems. The method has three steps: research problem identification and case study definition; criteria assessment (energy simulation, LCA, and LCC); results analysis. Investments in the building envelope can reduce 20% of energy consumption per year, 12% of Global Warming Potential emissions, and 17% of Cumulative Energy Demand. The assessment included two different scenarios of the electricity grid mix. The scenario with cleaner energy had a 25% reduction in the environmental impact. Thus, future potential changes in the electricity grid mix must be considered in building assessment because of the typically long building life cycle. The envelope adaptations improve environmental and thermal performance and influence the entire life cycle costs due to energy consumption. Thus, the results help in decision-making.