Exploring the relationship of building area and GHGe: a mitigation strategy?

Abstract Greenhouse gas emissions (GHGe) from new constructions must be reduced to address the climate change crisis. Life cycle assessment (LCA) is widely applied to document the environmental impacts of buildings, often reporting results by dividing the total emissions over the measured building area, such as the gross floor area. The appropriateness of this approach has been debated in the building LCA research community and the construction industry, with concerns about the potential consequence of designing larger buildings to reduce emissions over the buildings’ life cycle and if this entails easier compliance with limit values in regulations. With a large collection of 291 case studies divided into four weight categories, potential correlations between constructing larger areas and GHGe are explored by fitting linear models. The results show that theoretically, GHGe reported per area can be decreased due to increased building area. However, this requires significant increases in area, which realistically results in increased costs, resource use, and related environmental impacts, which is not feasible. Therefore, the findings do not support the notion that interpreting LCA results per square meter encourages the enlargement of buildings to reduce emissions over their life cycle. It should be noted that the study’s conclusions are drawn from the end results of individual LCAs. The potential decrease in GHGe by enlarging the building area during the design process is not possible to derive without involving stakeholders. Thus, this study underlines the need for future research to achieve a nuanced relationship between building size, design choices, and environmental impacts.