Environmental analysis of residential exterior wall construction in temperate climate

With the growth of the construction industry market there is an urgent need to evaluate the use of building materials from the sustainable point of view. Product stage of construction materials has a significant negative impact on the environment. This work represents environmental assessment of the construction materials of a low-rise residential building located in the temperate climate zone. To conduct such an analysis, we used a comprehensive methodology, product life cycle assessment (LCA), complying with international standards ISO 14044 and ISO 14025. The global warming potentials were calculated for the building life cycle product stages (A1-A3) in the equivalent of the carbon dioxide emissions (CO₂e). It was found that external walls have the greatest negative impact on the environment compared to other building elements. Production of construction materials for external wall structures is responsible for 45 % of the total CO₂e emissions. Based on the performed calculations, alternative options for exterior wall construction are proposed. Heat losses were calculated for each type of enclosing structures, as well as greenhouse gas emissions from burning fuel for heating the building. It was found that an aerated concrete wall with ventilated facade has the least negative impact on the environment, even though heating a building with such an enclosing structure requires more energy than other wall options. Environmentally reasonable approach of the enclosing structure selection allowed a reduction of greenhouse gas emission by 16.7 %, from 402.85 tons to 335.65 tons CO₂e.