LCA of the NZEB El Salvador building, a model to estimate the carbon footprint in a tropical country

Life cycle assessment (LCA) in buildings is an objective process that evaluates the environmental burdens generated by their entire life cycle. In this way, it works as feedback to the building design and construction process, highlighting better choices of materials and construction systems, when evaluating decarbonization strategies. This article summarizes the findings from the implementation of an LCA in a net zero energy building (NZEB) located in El Salvador, Central America, on the campus of the Central American University. The assessment determined the carbon and energy impacts generated by the building, with an emphasis on its construction systems, throughout the life cycle. Two LCA methodologies were applied. The first one was a simulation by means of the SimaPro 9 software faculty version and the Ecoinvent database, under the cradle-to-grave approach. The second one was a calculation aided by an interactive table created by Bath University, United Kingdom, which is based upon the Carbon and Energy Inventory (ICE) utilized for calculating buildings' built-in impacts under the cradle-to-gate approach. The main results highlight the importance of using renewable energy as a building's energy source, to avoid and compensate for impacts generated by other stages of the life cycle, for instance, the stage of raw materials extraction and final materials production, which generate the most significant impacts, from both the energy and carbon equivalent perspectives. Therefore, materials selection becomes crucial for reducing or avoiding impacts within a building's structure throughout its useful life. Also, applying circular economy principles through the reuse and recycling of materials is fundamental to minimizing the life cycle impact of a building in this context.