When Ulla Janson began her investigation three years ago, she found that the market was completely quiet. A change has now begun, and passive buildings are constructed in several places in Sweden. According to Ulla Janson, one explanation why development of energy effective buildings did not start earlier is that energy was relatively cheap. When energy prices rise, there are great macroeconomic gains to be made, especially in view of the fact that heating and hot water for offices and housing account for 36 per cent of energy use in Sweden. In addition, Sweden must become more energy effective to comply with the new EH environmental objectives.
The construction industry has long claimed that the new rules of the Swedish Board of Housing, Building and Planning, that the maximum consumption in new construction must be 110 kWh/m2, is too difficult to comply with, but according to Ulla Janson the limiting values for passive buildings are three times lower than the Board’s recommendations. It is thus perfectly feasible to construct low energy buildings.
Project leader important
All the conditions for constructing well functioning passive buildings do exist in Sweden, as regards both technology and knowledge. For increased construction to become reality, however, the key role of the project leader must be recognised. He/she must be very well informed and provide more information and help while work is going on. It is also necessary to increase the choice of components, mainly ventilation terminals and heat exchangers.
Despite the increasing interest, she and her colleagues still meet several myths about passive buildings. For instance, there is a fear that a well insulated and airtight building, such as passive buildings, runs the risk of damage by damp. Obviously, information that today's passive buildings have good ventilation must be disseminated even more.