The new energy requirements that apply to new houses have increased the amount of attention being paid to airtightness, i.e. the relative ability of a house to “leak” air. One of the critical leakage points in a building is the area around its windows. For this rea- son, SINTEF Building Research has been finding out which methods of tightening leakages give the best results on the energy barometer. Tape turned out to be the best of six methods tested.
Building tape installed between the window-frame and the wall itself reduced air leaks to zero. Second place went to wind-barrier strips, which left a leakage rate of 0.1 air changes per hour (ACH50), compared to the worst solution, where the figure was 3.2 per hour. The authorities require that the leakage figure should be no higher than 2.5 ACH50. The tests were carried out in the course of a doctoral study at NTNU, which formed part of a SINTEF research project entitled “Climate Adapted Buildings”.