In Passive House projects, the installed windows and doors must perform to a U-Value of 0.8 or approx. R-7. This is no easy feat, considering that there are issues of glass, seals, frame and installation to contend with.

The unit should have adequate seals to fully integrate with the air and vapour control layers, as well as thermal characteristics that blend with the insulation layer and mitigate bridging.

What you'll end up with are windows and doors built like a tank, that also cost you a pretty penny. Planning for performance in the building means carefully considering where and how many openings you are going to have. You can rest assured that your certified windows and doors will not become a failing part of the construction.