Abstract
A major contributor to global greenhouse gas emissions is the production of concrete and steel for the construction industry. This report presents a comparison of the life cycle GHG impact of a concrete and steel load-bearing structure with a wood load-bearing alternative. The basis for the comparison is a theoretical ZEB office concept of a four story Norwegian office building. The wooden structure causes approximately half the emissions of the concrete and steel structure. The results show that end-of-life emissions account for less than 10% of the overall GHG emissions from the load-bearing systems life cycle.