Building lifespan: effect on the environmental impact of building components in a Danish perspective

Construction professionals must now integrate environmental concerns with life cycle assessment (LCA) early in the procurement process. Building lifespan is important to LCA, since results must be normalized on an annualized basis for comparison. However, the scientific literature shows that issues of building lifespan are inadequately addressed. The aim of this research is therefore to explore how environmental impact from building components is affected by building lifespans of 50, 80, 100 and 120 years in a Danish context. LCAs are undertaken for 792 parametric variations of typical construction solutions, covering all primary building components and based on contemporary practice. A full statistical analysis is carried out, which shows a significant statistical correlation between changes in building lifespan and environmental impact for all primary building components, except windows/rooflights. On average, a building lifespan of 80 years reduces environmental impact by 29%, 100 years by 38%, and 120 years by 44%, all in relation to a lifespan of 50 years. The results show that if construction professionals and policy-makers use short building lifespans, then resource allocation to reduce environmental impact during procurement may become disproportionately focused on the construction contra operational phases of the lifecycle.