Airtight houses and energy consumption.

The perfomance of single-family houses built to the new swedish building code was considered. In the code, the requirements for thermal insulation for different building sections were strengthened, and completely new requirements for a building`s airtightness were introduced. One site- built design acheived a estimated 1/3 reduction in energy consumption, but another less airtight factory-made house showed serious shortcomings in the indoor climate acheived.