With the Europe-wide introduction of the energy certification for buildings (Energy Performance of Buildings Directive, EPBD, 2002) the accurate assessment of the thermal quality of buildings becomes increasingly important for building valuation. The energy certification is a means to predict the energy efficiency of a building and hence energy costs. In face of the rising and volatile energy costs this must be seen as a very substantial information for investors, tenants and building owners which potentially will influence their market behaviour: Values and rents of buildings with a high thermal quality will potentially increase, those of buildings which poor thermal quality are likely to decrease. To what extend this new situation will influence the market is not clear at this point of time, but building valuers have to consider this fact in the valuation process. Trying to derive reasonable approaches to consider energy efficiency in the buildings appraisal process, we int erviewed a number of buildings valuation experts in Austria. Our results give a picture of how measurements of energy efficiency could be included in the practice of building appraisal and how the introduction of the energy certification for buildings will change the real estate market.