The state of building stocks changes over time. Owners and municipalities face the choice to renovate or rebuild buildings to improve energy efficiency. This review addresses how current sustainability assessment tools support these decisions. It finds that advanced tools are better tailored to evaluate project level energy-related decisions than at larger scales. Information gaps identified within assessment tools lead to uncertainty for decision makers about which option improves energy efficiency. In the case of a number of large-scale EU building renovating/renewing projects these tools have been scarcely used or merely suggested during planning. Recent advances in sustainability assessment tools can begin to close some of the existing knowledge gaps, while incentives and stricter legislation may improve their usage rates.