Multi-active Façades for Renovation of Million Program Houses

Abstract: Sweden faces an upcoming period where thousands of buildings built during the million program period will be in need of a façade renovation. There is a large energy-saving potential in these buildings, since they are often poorly insulated and often have a ventilation system without heat recovery. Performing energy-efficient renovation measures to a building are expensive, which results in that the property owner does not undergo the renovation. This in return can lead to that the façades of the million program houses deteriorate. The aim of this master’s thesis was to map developed multi-active façade systems on the market, to determine if integrating multi-active façade systems to million program houses is a more energy and cost efficient solution compared to integrating traditional renovation measures separately. In order to accomplish this, a thorough market review was performed to determine the quantity of multi-active façades in Europe. Two prefabricated multi-active façade systems and one that is mounted on site were chosen to perform a deeper investigation of their energy performance and Life Cycle Cost. The analyses were performed by integrating the multi-active façade systems to a typical million program house located in Landskrona, which was used as a reference house. The condition of the façades of the reference house was better than expected, which means they are not in an immediate need of renovation. The multi-active façade systems were compared to both traditional renovation measures and the current status of the reference house. The multi-active façade systems reduced the energy use of the reference house as much as the traditional renovation measures. The total energy use was reduced by approximately 60 % and the heating demand by approximately 80 %. The most energy-efficient renovation measure to integrate was the balanced ventilation system with heat recovery, which also improved the indoor climate in the apartments. The energy-efficient measures did not, however, pay themselves off in the form of reduced energy use and thus lower running costs. This master thesis found that neither integrating multi-active facade systems nor mounting traditional renovation measures are directly profitable. Profitability can only be achieved when there is a need to renovate the façade and the costs can be covered by the maintenance cost, and not as an energy measure. One of the multi-active façade systems did, however, have the same cost over a 40 year period as traditional renovation measures. If the property owner could raise the rent with 316 – 699 SEK/month, all the renovation solutions would be profitable to carry though. The advantages of installing a multi-active façade system contribute to low disturbance for the tenants because of only few visits inside the apartments. Also, the construction time becomes shorter on site and the tenants do not need any compensation.