Earlier intercomparison studies have shown that already the calculation of floor areas, envelope areas etc. lead to different results when national calculation standards of several European Member States have to be followed. In most cases one or several representative buildings for the country that launched the study have been used for the comparison. As many influence factors are related to the floor area, other areas or volumes (e.g. default values for internal gains or the ventilation losses), this can produce the first differences regarding the energy performance results. Also the results of the comparison can be quite dependent on the type of building that has been chosen as reference building. This is valid for different types of dwellings (single-family house vs. multi-family house) as well as for residential vs. non-residential buildings.