Plastic windows crack in sunlight / thermal expansion

For me, everything is now handled through the lawyer. The creaking windows are still installed, hopefully they'll all be removed eventually...

I wouldn't put too much hope in the idea that legal action helps against incorrect material combinations chosen by the builder—nor in loosening screws; but perhaps a little in allowing the screwed joints to slide and converting the respective holes into elongated holes.

A great solution
You would surely do the same
Maybe they creak then too, then we'll just buy wooden windows, right

In fact, this creaking problem has been minimized with both aluminum windows and wooden windows. Aluminum can be very well used to make window profiles, as can wood. Plastic windows are basically steel tube windows at their core, meaning they consist of two main components whose coefficients of expansion do not harmonize well. Add "dark surface" and "south side," and the creaking effect reaches a disturbingly audible level. The material is not to blame for builders who have received poor advice.

Everything is now going through the lawyer for me. The creaking windows are still installed, hope they will all be removed eventually...

I read elsewhere that you once suspected that the problem was due to the roller shutter rails. Then the rails were removed from one window, right? Did that still not bring any improvement?

We had the same problem with our front door. The company came out several times, without success. After threatening with a lawyer, the department head came out, end of the story, the door was still produced as a custom-made item. The door was tight in the masonry, couldn't work.

Best regards

I have both defects in our house built in 2018, the cracking in the front door and the windows. It appeared almost exactly after 5 years, after the warranty period expired. The one cracking window is a fixed plastic window 290 x 170 cm in white outside and inside. It cracks with all temperature fluctuations, also in the dark, from a corner. If you press on the frame there from outside or inside, it creaks. The front door is made of aluminum, medium gray, and cracks terribly loudly when the sun comes and goes. It hangs on three hinges in the frame and if you loosen these a bit and adjust the setting a little back and forth, only the frequency of the cracking changes somewhat but it remains. In the living room next to the plastic window, I now take breaks with earplugs, it is terrible. What can I do?