Are the windows defective?

I think, during the warranty period this is often not a problem. At this time, many companies still give in. Later it becomes more difficult, because then the hidden defect must be demonstrated.

We always had big problems with the new windows. There were drafts in all corners and edges. The window installer also came several times, but that only lasted for a short time. So we then had this [Blower-Door-Test] done. That’s how the error was found, and it was between the window and the wall.