Is the price increase for the general contractor after signing due to raw material shortages lawful?

That is correct, but being right and getting your rights are two different things, which my post was meant to show. The typical additional costs you mentioned are simply a few percent higher. If he really wants those few euros from you, he will get them from you. A contract is never tight enough that you can’t squeeze out a few more percent. We’re not talking about huge sums here; those have already been defined by the contract.

That then depends on the general contractor again... But yes, that can always happen to you—whether you “clash” with the general contractor in this area or not. Ultimately, it’s a matter of principle... You don’t hold it against the customer at all. The general contractor simply tries it because, of course, he wants to make more profit. It’s totally transparent and simple in essence.

The general contractor simply tries it because, of course, he wants to make more profit? From the matter itself, it's totally transparent and simple?

But the general contractor doesn't get rich from a single house either. What does he earn from it? 10-20%. With planned construction costs of €350,000, that's between €35,000 and €70,000. So the general contractor quickly considers how much passion to put into a project that, after price increases, might only yield €15,000. But it offers a stressful year and it’s still a profit before taxes.

That has to do with professional or amateur (P.S. The customer is not borrowed ;-) )

Thank you for the note. I have dyslexia. So please excuse me if I write it wrong again sometime.

But even with a house, the general contractor doesn't get rich. What does he earn from it? 10-20%. With planned construction costs of T€ 350, that's between T€ 35 and T€ 70. So a general contractor quickly thinks about how much heart and soul to put into a project that, after price increases, might only yield T€ 15. But it offers a stressful year and is still a profit before taxes.

Believe me, if it’s a large general contractor who builds 10 houses a month and then has problems with 10/50 clients, he simply accepts the lower margin... Everything is calculated with contingencies anyway; as long as the annual contribution margin fits, it’s perfectly fine. He offsets the amounts in ongoing/upcoming offers (construction continues anyway).

If a general contractor builds 2 houses a month and has problems with 2/10 clients, it’s the same game...

It doesn’t change anything about the matter – the stress the general contractor has is no different from the client’s stress. Psychologically you’re right – the client certainly has the bigger problem – ultimately the general contractor will never put himself through that stress and try to get out of the contract and chase the project with lawyers for years. He simply pays the extra €10,000 and that’s it!

For the general contractor, it’s much less stressful to simply build the house for a lower margin than to deal with the stress afterwards!

That brings us back to the topic: This is also the easier solution for the general contractor! A company almost always chooses the easy way in such matters!

Additional costs then just end up being a few percent higher. If he really wants those few euros from you, he'll get them from you. No contract is ever tight enough that you can't squeeze out a few percent more. We're not talking about huge sums here; those have already been defined by the contract.

Well, I would argue that there are hardly any people here who don’t have additional costs in the double-digit percent range. That may be little for you, but with today’s housing costs, that certainly hurts some.

Simple solution from the general contractor.
If the customer is not willing to be lenient, then he includes it in the change orders.
And there will definitely be change orders.

These are then often neither checked whether they are justified nor whether the amount is correct. Next lesson learned for the client.