Soundproofing for windows in living spaces

Good day,

our developer has blocked our windows so that many can only be tilted slightly. One window not at all. He says this has to be done for soundproofing reasons. What is this about? Is there a set of rules that states how much noise may enter through a tilted window? He cannot just eliminate the functionality. Aren't there other ways?

Thank you very much for the information.

our developer has blocked our windows so that many can only be tilted slightly. One window not at all.
He says this has to happen for noise protection reasons. [...]
But he cannot just remove the functionality.

I would give him a good talking-to (only for his own good, of course). Seriously: no, he is under no circumstances entitled to do that. Send a registered letter with acknowledgment of receipt demanding immediate removal of the blocking, setting a deadline of one week from receipt of the letter, which should be appropriate in this case. In case of non-compliance, announce reporting for bodily injury and deprivation of liberty as well as a substitute performance at his expense. Address it to the managing director c/o the company’s registered address, and in addition to "REGISTERED LETTER / acknowledgment of receipt," put "URGENT! – please present immediately!" before the subject line. He’s probably completely out of his mind. This is not legal advice – that is available from a lawyer – but merely a glance into the crystal ball of what he will tell you. It is now Friday after 12 pm, so lawyers are usually already off for the weekend. But for Monday morning, you now know what you intend to do.

What is that all about?
Is there a regulation that says how much noise is allowed to enter through a tilted window? [...] Aren’t there other ways?

The reason for this is that the guy probably could not get soundproof windows delivered on time. Such windows, also with certain specification requirements, can be stipulated in a development plan and be a condition of the building permit. Every open window lets in less sound than a closed one, but that does not make a closed window a proper sound protection measure. Here, the health hazard from reduced air exchange rate (at least if no controlled residential ventilation is installed) and the life-threatening danger due to blocking the second emergency exit in case of fire clearly outweigh.

These are already triple-glazed windows. It is quiet when closed. You can open them fully. Just not tilt them properly. We are already working with a lawyer. But once they work properly again, the question of soundproofing remains. It is already very loud. But air exchange is urgently necessary.

These are triple-glazed windows. When closed, it is quiet. You can open them fully. Just not tilt them properly.

Oh, you can open them wide, but not tilt them properly? – The number of panes says little about that.

We are already involved with a lawyer. But once they are fully functional again, the question of soundproofing remains.

So the lawyer is handling a complaint about a sticking opening mechanism? Soundproof windows are a level of equipment; the manufacturer’s data sheet should also show which measures and results (measured values) are achieved. Proper installation is very important too!

Is there a regulation that states how much sound is allowed to enter through a tilted window?

I wouldn't know what open windows have to do with sound insulation.

Tilting the window hardly does anything for air exchange. Of course, it has nothing to do with your deficiency, but it's better to open the windows for 20 minutes with a lot of noise than for 5 hours with a little noise... And by the way. How is an open window supposed to provide sound insulation, whether tilted or fully open?