Greenhouse gas reduction strategies for building materials: A reality check with the climate targets

The increasing importance of the embodied emissions in the life cycle of buildings has led to a growing interest in strategies supporting their mitigation. In this paper are presented the environmental impacts of 10 variants of a single-family house assessed with the life cycle assessment (LCA) method. A set of potential technological improvements and strategies are applied at the material level. Their influence at the building level is discussed and the resulting global warming potentials are compared to the COP21 targets for Austrian buildings. Finally, potential trade-offs in 9 other environmental impact categories are explored. The results show that, when incorporating all of the assessed strategies for emission reduction, the embodied greenhouse gas (GHG) emissions could be reduced up to 87% at the material level and 50% at the building level. Carbon capture and storage and the use of bio-based materials are to be credited for the highest share of these reductions. However, there is no version of this building that fulfils the COP21 targets. Other pathways, which do not solely rely on material-related technological improvements, should be investigated. A more radical change of the building industry might even be necessary. Overall, the implementation of the strategies decreased the environmental impacts in almost every impact category, except for freshwater aquatic ecotoxicity.