Profitability of Energy Saving Measures in Existing Residential Buildings: Fid-Bau Portal

Profitability of Energy Saving Measures in Existing Residential Buildings

L. O. Rejstroem / U. Blomberg

The profitability of energy saving measures was studied in existing residential buildings. The most common energy saving measures in detached houses were additional roof insulation, installation of thermostatic radiator valves and installation of a third window pane. In row houses installation of thermostatic radiator valves was the most common measure. In apartment houses installation of thermostatic radiator valves and connection to district heating were the most common measures. In the study energy consumption data was also collected from residential buildings where no energy saving measures had been undertaken. On the basis of this reference data the energy consumption in the buildings, where measures had been taken, would have decreased 2% per year in any case due to changed energy consumption habits. Considering this, the energy consumption has decreased 14.0% in apartment houses, 13.9% in row houses and 10.2% in detached houses, due to energy saving measures. The profitability of the measures was calculated on the basis of the energy savings and the total costs of the measures given by the respondents. The average internal rate of return of the investment was 30.8% in apartment houses, 27.5% in row houses and 8.1% in detached houses. The average payback time was 3.0 years in apartment houses, 3.6 years in row houses and 9.7 years in detached houses. The most profitable measures were connection to district heating, installation of thermostatic radiator valves and installation of a third window pane. The only clearly unprofitable method was additional insulation of the walls. (ERA citation 12:011543)