Framtidens trähus— energieffektiva med god innemiljö.

The report presents documentation of the critical points during the development, planning, and building phases of the first multi-storey apartment buildings built in timber prefabricated construction according to the voluntary Swedish passive house criteria.

Besides choice of the construction details, building elements, and technical systems the report includes results from blower-door tests as well as the energy analysis of building's heating needs and achieved summer indoor temperatures. Finally a comparison was done with a reference building Limnologen, which was built according to the energy requirements in the Välle Broar area in Växjö.

Simulations show that the Southern Portvakten building has 33% less power need for heating than if the same building was built as the Limnologen building, while the heating demand is 41% lower.

A program for following the energy performance of the building during the first year in operation is also presented. Energy simulations were done in the DEROBLTH program.