The recent IPCC 2023 report reiterates that humansare responsible for global warming over the past 200 years, causing a rise temperature of 1.1°C above pre-industrial levels, as well as an increase in energy demand, which can be avoided with mitigation options, reducing its use in all sectors, especially in the building sector. One of the options is the design based on the NZEB concept, as it has been the case of the laboratory built on the UCA campus, using passive and active energy efficiency strategies, studying the interaction between construction systems and energy savings. One of the NZEB El Salvador project research objectives, was to study the thermal performance of different construction scenarios, therefore, the present work presents the results of the Life-cycle assessment(LCA) in three proposals for popular construction systems in El Salvador, regulated by the national regulatory framework, comparing them with the baseline of its current operation, through 3 iterative calculation tools: structural, thermal and carbon footprint estimation, managing to find importantfindings on how vernacular systems meet the NZEB standard. ILIA: Investigaciones Latinoamericanas en Ingeniería y Arquitectura, No. 01, 2024: 160-166.