Life cycle assessment in net zero energy building scenarios in a tropical country

Abstract

The recent IPCC 2023 report reiterates that humans are responsible for global warming over the past 200 years, causing a rise in temperature of 1.1 °C above pre-industrial levels, urging the implementation of mitigation options, especially in the building energy sector. One strong mitigation strategy is designing and building net zero energy buildings (NZEB), although their implementation faces challenges such as opposition to change, especially in tropical countries with traditional and conservative design and construction practices. This paper uses data from a pilot NZEB Laboratory building at UCA, El Salvador, and details its results by comparing different construction system scenarios. The present work presents the results of the Life-cycle assessment (LCA) in three popular construction systems in El Salvador, comparing them with the baseline of its current operation, through 3 iterative calculation tools: structural, thermal and carbon footprint estimation, managing to visualize important findings on how vernacular systems could meet the NZEB performance with added insulation in the structural walls. In addition, a triple-axis sustainability analysis (environmental, economic and social) is conducted using the weighted criteria matrix, which provides nuanced results, such as the proportional share of embodied carbon between the proposals, there is not much difference between the results of the proposed systems, but compared to the baseline, the proposals represent a significant increase of more than 50%. Our results show that in this context, the scalability of NZEB buildings is feasible for different construction systems, paving the way for a progressive and incremental.