The main aim of this thesis is  to demonstrate and critically assess life cycle approaches’ and environmental certification (EC) tools’ potential for supporting decisions for improved environmental performance in the building and real estate sectors. Using life cycle approaches, the thesis shows that for new build and renovation cases aiming for low operational energy use that embodied global warming potential (GWP) due to material production can constitute a large portion of a building’s lifetime GWP. Therefore life cycle based information about materials’ embodied GWP needs to be made available to and utilized by design process decision makers. It was also shown that applying the Swedish EC tool Miljöbyggnad was useful in highlighting potential positive and negative changes in indoor environmental quality arising from renovation packages aiming at significant operational energy use reduction in existing multifamily buildings. However such renovation packages are not profitable from a property owner perspective. Miljöbyggnad may be useful when designing policy instruments to overcome this.    The thesis also showed that EC and related environmental enhancements contribute to achieving property owners’ and tenants’ overall strategic objectives for value creation. For property owners this arises for example through lower energy costs and attracting desirable tenants. For tenants, value creation arises as support for internal and external environmental communication. For the further development of life cycle approaches’ and EC tools’ application to buildings and real estate it is important to consider how they can be adapted to consider ‘distance to sustainable’ targets referencing for instance the planetary boundaries approach. It is also interesting to investigate how valuation of buildings and real estate may be performed in a way that expands from the current narrow focus on the economic perspective to also include environmental and social perspectives. / <p>QC 20170210</p>