Carbon footprints are commonly used to assess environmental properties of building products, for comparisons of similar products and in order to minimize the environmental impact of products and projects. A carbon footprint is calculated with the use of life cycle assessment (LCA), where the emissions from cradle-to-grave are accounted for as well as emissions from upstream production like electricity. Sawmill production is a multiple output system and the choice among the methods on how to allocate the footprint have previously shown to be important. This paper finds that methodological choices for electricity mix and carbon cycle of bioenergy of a potential much larger importance. The Norwegian electricity mix is almost carbon neutral, but a change in practice to international mixes can have large impacts. Bioenergy from forests have up until now usually been regarded as carbon neutral, but an approach with carbon dept will make the emissions almost half of fossil fuels. The present article aims at providing an overview of previous LCA studies and comparing the results with recent LCA studies carried out in cooperation with Norwegian sawmill industry. This will show the possible effects for the carbon footprint of sawmill products from a changes in common practice for the choice of electricity mix and including an accounting of the carbon cycle of bioenergy.