Is building in Bavaria still possible for 500k?

What is objectionable about normal plastic windows? What do you have in mind anyway?

There is nothing objectionable about them at all, I just don't find plastic windows very attractive unfortunately. That would have been one of the few points where we would have been reluctant to save. But as a previous speaker has already pointed out, with the available budget plastic windows are the least of our problems :-/

So friends of ours were also first in Poing at the show house park and the prefabricated house providers all quoted prices of 3000-3500€/sqm for average standard.

For 500k it is probably possible, but double garage and basement are cut.
I would also initially remove the carport.
Then I would get offers for 150-160sqm or choose a suitable show house and see where you actually end up.

You can easily add the carport later or even the double garage then.
With a total budget of 1.1 million, it might turn out in 5-10 years that 100k more was also affordable.

but the double garage and basement are canceled. I would also remove the carport for now.

I would mainly consider: what can I (for example, if I have short-time work for two months in 2024) build MYSELF afterwards? For something simple like a carport, I trust my own effort ... stacking a few pallets of bricks into three walls = building a garage with a roof on top and a gate on the front side should also be "doable"... Adding a basement afterwards is probably rather difficult?

Is working from home an option? Then the search radius could be increased a bit. With ~20 minutes travel time to Ingolstadt, there are still a few spots on earth that cost less than 1k/sqm.

Is working from home an option? Then you could increase the search radius a bit. With ~20 minutes drive to Ingolstadt, there are still a few spots of land that cost less than 1k/sqm.

Unfortunately not, 80% presence is required.

It will be fine - many go through this development. I also once thought that if I build, then big wood-aluminum windows, controlled residential ventilation, maybe even a pool if something is left over - now it's none of that, plastic windows, ventilated with rebates and swum in the quarry lake, I'm glad the blinds are electric. The budget is still exceeded... Walk through a good residential area where fancy new buildings stand - 95% plastic windows even in the new villas... GD