Wait with the windows until the roofer is finished?

Hello dear community,

my shell construction is complete. Next week the roof truss is supposed to be installed and then the roof will be covered. My builder says he wants to install the windows only after that. Does that make sense? I have concerns, as nothing will happen for 4 weeks except the roof. In my opinion, the interior work could take place in parallel. It is a 4-unit house, about 16x16m and two full stories.
As a reason, he says he doesn't want the windows to get damaged if something falls during the roofing work.
What do you think about it?
Best regards
Tommy

The interior work should only start when the house is "sealed" - that is, when the windows are in *and* the roof is on. Depending on what is being done (drywall?), otherwise it can really cause problems.

Apart from that: Are you having the entire house built? Otherwise, the developer will (really?) probably not change their way of working just because of a single apartment buyer.

It would also be very unusual if he already has the windows immediately after the shell construction. Normally, they are only measured and manufactured afterward. If it currently only takes 4 weeks there, everything has gone very well.

I am having the house built by the developer and renting out all the apartments. What can be done in parallel to the roofing?

What can be done in parallel to roofing?

Waiting? ;) Otherwise, sampling equipment, applying for house connections, ... at most maybe preparing electrical/plumbing installation (milling slots).

It would also be very unusual if he already had the windows right after the shell construction. Normally, they are first measured and manufactured then.

I would rather assume that windows with standard dimensions are used and thus are stock items. Custom-made individual production is simply too expensive nowadays.