Unpredictability of construction costs - Will the project fail because of it?

There have now been over 100 posts on such an existential topic since last night. Read everything through again calmly, gather yourselves a bit, try to find out which points are most important for your decision-making now, and then try to approach it systematically with the people who know a lot here. It's not the case right now (if I am seeing this correctly) that a decision has to be made within the next 24 hours.

It is not that I categorically exclude it. I just don’t know how that is supposed to work right now! Stay with the old construction company or try to find a new one? What about the loan if we redesign the property and leave out the basement? Those are questions I can’t answer immediately!

Oh man, you poor things, that is really a crappy situation. I think it’s good and impressive that you still don’t bury your head in the sand and face this discussion. I can’t give you any advice, unfortunately, but there are many smart people here who will show you ways. I hope you get through it well... It is simply the worst possible time to plan a house build.

How is he supposed to just rearrange the whole thing like that? Is it really that easy? I mean seriously, I don't see how that could just work like that? The loan is running and whether the bank will simply agree to a changed property, I would seriously doubt. Potentially a new loan with completely different interest + non-acceptance fee for the current loan? Additional costs for rearrangement with the general contractor? Potentially months of processing time and rising costs during that time? Additional costs for new building application and new building permit? Is the whole rearrangement still "economical"?

I ask myself the same, this topic is apparently completely overlooked. Small things, yes, then a storage room is just added in the basement. But for example leaving out a floor would mean starting completely from scratch. Finding another construction company while all are booked for years is also impossible. People imagine all this easier than it actually is in the end.

Since last night, over 100 posts have been made on such an existential topic. Please read everything through again calmly, gather yourselves a bit, try to find out which points are now most important for your decision-making, and then try to approach it systematically with the people who have a lot of expertise here. It is not the case right now (if I have correctly assessed everything) that a decision must be made within the next 24 hours.

And how do I know who has expertise here and who doesn’t? I can talk a lot too, all day long..
As mentioned above, it is recommended to reschedule, but whether that makes sense due to consequential costs no one can answer either.

Arrange the on-site meeting (not by phone) with the construction company. Try to find a compromise on the price increase. With the statement from the lawyer as well as the demonstrably unbuildable plans (basement height), you have two solid arguments.

"I understand that the costs for purchasing steel and other materials are shrinking your margin, but on the other hand, I have a valid contract and have adhered to all deadlines written therein. However, I want to achieve a proper house construction with you together despite these difficult times. What do you think about agreeing to split the additional costs halfway?"

For example. Of course, you need the exact figure of their additional cost calculation beforehand.

Uiuiuiuiuiui, ouch ouch ouch ouch. Urgent (specialist) legal advice is required here: There is a valid construction contract – however, for a house that, as offered and built, will not receive KfW funding due to the insufficient ceiling height of the granny flat (the approval does not help anymore if the agreed basis is not created). The advisor, who apparently acts independently of the exercise of due diligence, is useless, and the builders have learned that a release clause is a double-edged sword. Because the construction is permissible as is, but the granny flat cannot then be inhabited. At that point, the fee for a proper approval process would already have paid off. There is price potential to omit the garage – if it were ordered separately and has not yet been ordered bindingly. If it were part of the construction contract as the plans suggest, omitting it would mean a partial termination and would invalidate the valid price lock-in. Given the size of the construction project – which in reality does not shrink simply because the builders perceive it as more modest – I can only be shocked at how naïvely the project was approached in all respects. You get better informed when buying a TV :-(

Ceterum censeo, the energy consultant and the financing consultant should marry each other, they obviously go perfectly together *ROTFL*

To the questions of understanding and others “all in one go,” so as not to scatter in fragmented quotes:
1. the contract was concluded by acceptance of the offer; the acceptance was declared by the builders on the offer.
2. if it contained no side agreement a) about further details (and which ones) still to be discussed and especially b) about which execution deadlines should apply, these are probably irremediable oversights :-(
3. a price guarantee time limit does not imply that the contract is dissolved at the end of the price guarantee period.
4. “without obligation” logically only applies to an offer until acceptance.
5. without further agreements, a price guarantee is completely worthless after its expiry; its continuation as a basis for limiting increases would have had to be agreed.

How one can be so careless to order “1 piece of extended shell construction according to drawing” in writing, but otherwise as casually as ordering a pizza, has now become a textbook example of why one cannot appreciate the value of a proper tender enough. Nothing in home building offers more saving potential than refraining from such blank check house orders. Without a construction service specification and an execution deadline agreement (with penalties!!!), a general contractor construction contract is worthless!