Life cycle assessment and energy efficiency of building façade materials: A case study of an educational building in Pakistan

Buildings consume energy throughout their life cycle, from initial construction to operation. The building and construction sector accounts for 40-50% of greenhouse gas emissions and uses 30-40% of total primary energy. Buildings can last for over 50 years, making it crucial to predict future building responses to climate change and evaluate potential changes in energy consumption. This novel research focuses on life cycle assessment for 60 years and the impact of different fa & ccedil;ade materials (wall, plaster, window, insulation) on operational energy and equivalent carbon emissions of an existing educational building in Peshawar, Pakistan (ASHRAE zone 2B). For the base case building, the total embodied carbon is 1250.4 tonnes, while for the proposed case, the embodied carbon reduces to 451.1 tonnes, marking a 63.89% reduction in CO2 emissions. Switching from clay brick wall (W8) to concrete block lightweight (W1), the most efficient one, reduces peak cooling total load (PCTL) and CO2 emissions by 16.4%. Similarly, changing plaster materials from cement plaster with sand aggregate (P5) to lightweight plaster (P1) results in reductions of 8.92% in PCTL and CO2 emissions. The PCTL and CO2 emissions are reduced by 10.55% when two inches of polyurethane board insulation (WI1) is added to the external walls compared to those without insulation. Moreover, replacing the clear glass windows with single, double, and triple-glazed windows with a shading coefficient (SC) of 0.2 results in reductions of 10.3%, 16.4%, and 17.5% in PCTL and CO2 emissions.