Renovering av flerfamiljsbostäder inom miljonprogrammet ur ett energi- och lönsamhetsperspektiv

Miljonprogram is a Swedish building program from 1964 to 1975. During that time about a million homes were constructed. Now, almost 50 years later, they are in desperate need of renovation. In order to fulfil the Swedish environmental objective to decrease energy consumption 50 per cent until 2050, considerable housing stock built under the Miljonprogram has to be renovated. Focus in this thesis is on the building services and theirs profitability that can decrease energy consumption in households build during the Miljonprogram. Building construction is not considered in this report. This thesis includes a literature review of existing housing stock and the exploration of the three renovated projects Brogården in Alingsås, Gårdsten in Gothenburg and Katjas Gata 119 in Gothenburg, where energy savings and profitability was evaluated. It turns out that the three real estate companies have different views on profitability, while one considers socio-economic profit the other one takes into consideration increase of rent level and construction experience. The three real estate companies use different repayment periods which affects the profitability of various measures considerably. I the case study on the miljonprogramʼs building Siriusgatan 24-28 various building services are examined and evaluated separately and in combination in order to estimate theirs energy saving and profitability. The results of the cost-benefit analysis show that charging for hot water, installation of low-flow faucet nozzle and replacement of exhaust fan is profitable whilst they are those measures that save least energy. Installation of ventilation system with heat recovery (FTX) and exhaust air heat pump (FVP) do not prove to be profitable. The option that provides the biggest profit while saving most energy is a combination consisting of charging for hot water, low-flow faucet nozzles, replacement of exhaust fan and installation of FVP system. At higher energy prices FTX system will be profitable because of the high energy savings that it provides. The results are affected by the assumptions and the fact that calculation models are a simplified reflection of reality