European Energy Performance Building Directive

The main goal of this paper is to assess alternative exterior walls options to support decision at project level of new buildings in Portugal towards reduced life cycle energy and environmental impacts. A life-cycle model for buildings has been developed focusing on alternative external wall systems (single, double) and contemporary materials. A comprehensive life cycle impact assessment (LCIA) is presented, including results for two well-known LCIA methods: CML2001 and Eco-indicator’99, which are compared on their performance through application to the same life cycle inventory for a single-family house in Portugal. Key Words: Building envelope; environmental impacts; life cycle assessment; single-family house. 1