The purpose of this project was to map the construction and of a house built in 1953 and calculate the energybalance for the house in its original design. The idea was to investigate the measures that has been taken to lower the energy use in the building and see how great the savings were after each measure in the specific order they were made. The reason for choosing the there is possibility in saving energy in the residential sector The energybalance were calculated by hand for the building in its original design and the energy efficient measures that were examined was additional insulation of the attic, window replacement and installation of a heat pump. The result for the buildings energybalance is that the demand for active heating is about 20 000 kWh/year. That can be compared with the result for calculation of the original oilfired boiler that were 13 600 kWh/year. The energyefficient measures that were made showed that the additional insulation gave a 11 percent saving of the demand for active heat. windows that were replaced and sealed gave an additional saving of 0,3 percent. That is because the measures of the windows result in two positive effect regarding the transmission- and ventilation losses and one negative effect regarding the passive heat. the measures lower the demand for active heat from 20 000 kWh/year to 17 500 kWh/year. Installation of a heat pump covers 48 percent of all bought energy and covers approximately 10 000 kWh/year of the demand for active heat. Keywords: energybalance, demand for active heat, heatlosses, passive heat, window, additional insulation, heat pump