Delay in window delivery; still install sanitary/heating?

Hello everyone,

we are building a single-family house in timber frame construction with a regional carpentry company in BW. The house will be erected at the end of November. Since we are awarding all other trades individually after the shell construction, the window installer should start immediately and close the house. Unfortunately, there are scheduling problems with them and the windows will only be delivered around mid-January.
However, the sanitary/heating installer is already scheduled for early December. Now we have the problem that our house is "open."

Can the other trades still proceed or what options are there for "sealing" the window openings?
Is it sufficient to tape them with foil? Or are there other ideas?

Many thanks in advance for your support.

Main reason why the house is closed up beforehand is the theft risk of heating and sanitary items. At least, that's what they told us. Therefore, I don't think a foil would help, as it could simply be slashed open.

I have seen wooden inserts like that in doors before, but not yet in windows. Then you would also run into the problem that the house would be dark inside. Utility connections / electrical installations are probably not advanced enough yet for a building envelope?

Yep, I would be careful there too.
As far as I know: stuff gone, your problem.

If it is important to you, you can screw OSB boards from the inside. Maybe you can get some cheap used ones somewhere or rejects. Maybe ask at the sawmill or your home construction company might have an idea. It doesn't have to be nice - just effective.