Purpose: This degree project aims to show the energy demand for active heating for a residential building from 1936 in Vasteras. At new built and for both a real and a planned change. It also aims to put light on important factors for vertical allocations. Method: To show the energy demand for active heating calculations were made for the energy demand for each month. The residential building was studied to gather information to the calculations and a literature study was made to gather information in the subject. Results: The energy demand was highest when the house was new built in 1936. To become the lowest after the renovation in the 1980s. After the planned vertical allocation, the calculations gave a value between the first two cases mentioned above. The heat losses were also highest when the house was new built 1936 and lowest after the renovation in the 1980s. To increase after the planned vertical allocation. Conclusions: The vertical allocation in this study could not make the object of the study more energy effective. Then it was after the renovation. And the heat losses sank at the renovation but increased again at the vertical allocation. There are nine big experiences that must be taken into consideration when a vertical allocation is about to be made.