Life cycle assessment and historic buildings: energy-efficiency refurbishment versus new construction in Norway

Refurbishment policies for the historic segment of the building stock must be carefully promoted in the process of addressing the transition to a low-emission society to avoid the loss of the values which make this heritage significant. This article presents and the results of a Norwegian life cycle assessment comparing the net climate benefits from the refurbishment of a residential building from the 1930s with the construction of a new building in accordance with modern building codes. The results show that a careful refurbishment of the historic building is favourable in a climate change mitigation perspective over a 60-year period of analysis. For the new building, it takes more than 50 years for the initial emissions from construction to be outweighed by the effects of lower in-use energy consumption. The results underline the significance of emissions from the use of materials in the refurbishment process and that residents play a critical part with respect to realising the expected energy savings. It is concluded that material use and user behaviour have a crucial impact on greenhouse gas emissions in a life cycle perspective and that the continued use of historic buildings should be advocated for in building codes and environmental policies.