Fixed price commitment - price increase after expiration?

If you had started 2 days later, the BU could have already demanded this price increase according to the index. That’s just how it is, the price binding only means that the price is fixed for this period. The price increases that theoretically occur on the normal market during this period therefore only become relevant after the deadline has passed, but then also retroactively. Your point of view, no offense, is very naive and one-sided.

How exactly the start of construction is defined should be stated in the contract. You would have had to give the "Go" and created all the conditions for a potential start of construction. If then the BU cannot start, that could possibly be their problem. But if it comes through correctly, then you didn’t manage to get everything arranged for a start of construction within the deadline. Or what was the reason?

How exactly the start of construction is defined should be stated in the contract. You would have had to give the "go-ahead" and created all the prerequisites for a potential start of construction. If the builder then cannot start, that could possibly be their problem. But if it comes through clearly, then you did not manage to arrange everything for a start of construction within the deadline. Or what was the reason?

I would even claim that the timing was not achievable at all....

December: Signing of the contract for work February: Confirmation of the contract for work March: Meeting with the architect May: First drawings received June: Corrections completed and drawings confirmed July: Construction application documents received and submitted September: Construction permit received Our fixed price was only valid until the end of August.

I wonder how this is supposed to be managed at all (and even 3 months until the construction permit is not uncommon)

If it already takes 6 months until the construction application documents are there, then I can't do anything about that either.

If it already takes 6 months for the construction application documents to arrive, I can't do anything about that.

Hehe - if you hadn’t made any corrections, you would be further along already today. The general contractor can’t do anything about that. You can also look at it that way...

Hehe - if you hadn’t made any corrections, you’d be further ahead today. The general contractor can’t be blamed for that

You can also look at it that way...

The corrections only took 1 month... I’m more wondering why it took 2 months until the first drawing. That borders on delay.
And I think corrections should be allowed.
I will definitely address that and maybe also consult my lawyer.

Ok, it might be necessary to clarify who is responsible for the delays and whether the fixed price commitment was never realistically achievable. But keep in mind that you still want to build the house with the general contractor, so damaging the relationship irreparably with a lawyer before construction begins might not be a good approach. It might be better to first have a calm conversation. For example, why did it take 2 months to confirm the contract for work? Why then only 2 or a total of 4 months later to get to the architect? Could you have started immediately upon receiving the building permit?

However, I find it logical that the contractor gives you an offer with prices as of 15.02. on 15.02., and you now have to bear the price increase from 15.02. until today.

I don't think so. The builder would be out of his mind if he didn't already anticipate the price development from 15.02. until the end of the price commitment or start of construction in his calculation. He knows very well that construction cannot (or will not) begin within a few weeks after the contract is signed; therefore, he must assume the worst case, that construction begins on 29.09. and his costs arise under the conditions valid at that time.

Since the price commitment has now expired, his calculation is no longer correct and he rightly demands a surcharge. However, this can only be based on the actual, previously unconsidered cost increase, which is that after 30.09.

But this should probably be assessed by a lawyer. Lay opinions rarely help in such matters.