Carlsson A, Kronvall J.
Bibliographic info:
5th AIVC Conference "The implementation and effectiveness of air infiltration standards in buildings" Nevada, US, 1-4 October 1983

The air tightness of 15 detached houses was measured firstly immediately after erection and secondly after a period of 1.5 to 4.5 years. All the houses were timber framed ones, equipped with mechanical ventilation systems. Only two houses out of the 15 tested showed clear changes in air tightness. Thus the air tightness behaviour of the houses seems to be fairly constant.