The window installation in the insulation level (EWI) for a new build was realised at the beginning of 2022 by using steel brackets. This results in an increased installation effort as well as a
potential deterioration of the overall thermal insulation value of the window (as you can see in the Passive House Institute study further down below).
Since the load is only transferred at certain points, the correct dimensioning of the fasteners is also extremely important and potentially challenging.
The outer sealing level, to prevent water ingress, is very difficult to create, because the steel brackets hinder a clean and continuous seal. Likewise, the insulation material must be
recessed around the brackets, which can easily lead to thermal bridging.