One of the main objectives facing climate protection targets is how to deal with the existing building stock. Refurbishment measures are essential to ensure sustainable urban transformation. Life cycle assessments (LCAs) enable refurbishment measures to be evaluated holistically at the environmental level. However, there is still no sufficient methodological basis for the uniform evaluation. This present paper proposes a new perspective for comparing the continuing use with refurbishment as well as the demolition and new construction of a building. Thus, two new indicators are presented and elaborated regarding refurbishment measures: sustained emissions and the avoidance potential. To verify and validate the newly developed methodology, we implement it as part of this case study. We compare the environmental impact of a building’s continuing use with refurbishment measures as well as demolition and a replacement building with functional equivalence. The results indicate the environmental benefits of refurbishment measures compared to other approaches towards existing buildings. Although new buildings typically possess a superior energy standard, nevertheless, irrespective of the major impact of operational energy, refurbishment measures appear to be the most viable option for dealing with existing buildings over their life cycle.