Level(s) compared to European and Norwegian standards for life cycle assessment of buildings

Abstract

Launched in 2021, the EU Level(s) calculation method for Global Warming Potential (GWP) of buildings could get increasing attention and complement the standards that are currently used in Europe and Norway, EN 15978 and NS 3720. To understand the possibility and consequences of using Level(s) in Norway, we assess how the Level(s) GWP calculation method differs from EN 15978 and NS 3720, and whether it is more specific and provides more guidance. Comparing fifteen methodological aspects, eleven were treated differently in the three methods. Both Level(s) and NS 3720 are based on EN 15978, hence they provide more, though different, specifications and guidelines than EN 15978 for most of the aspects, such as scope of building elements, life cycle stages to include, and reference study period. Level(s) provides more guidance for the development of scenarios for the operational and end-of-life stages, and for assessing data reliability. NS 3720 lists the scope of building elements in detail and accounts for operational transport (stage B8). Overall, a building GWP calculated with NS 3720 would need some adjustment to reflect the prescriptions of Level(s). These findings inform LCA assessors about key differences, supporting the broader use of Level(s) in Norway as in Europe, and helping towards a harmonization of NS 3720 to Level(s).