Surcharge due to rising prices

The legal fact is that in the described constellation, the contractor has apparently unlawfully shortened the price binding period. On the other hand, he would have a whole toolbox of less subtle (though not legally actionable) ways to "take revenge" on the client if the latter refused him the solidarity here that could probably be called "symbolic."

Yep, that is a very difficult balancing act in which, in the end, everyone has to decide for themselves what to do. On the other hand, is also right. What prevents a construction company from taking the whole hand right after the finger?

In the contractor, presumably inferred from the OP’s nickname, organizational structures are likely to be assumed in which the described communication quality is considered usual in our experience. Anyone who does not like this culture should not go to the big names but must build with the small bricklayer master around the corner.

Whereas the communication culture of small companies is not necessarily better either. There you might get directly to the boss, but he lacks any finesse in communication. Emails are read once a day, if at all. When you call, the boss is on the construction site and the phone is in the car. And when he finally calls back, he is guaranteed on the road and steering right into dead spots ;)

Although the communication culture of small companies is not necessarily better. You might get straight to the boss, but they completely lack any finesse in communication. Emails are read once a day, if at all.

You don’t have to take me so literally, I actually meant the medium-sized master bricklayer around the next corner, just big enough for a full-time secretary. You call her. Emails are total nonsense, they get printed out and reading time is indeed only once a day, so what. But he stands on his own family name in the wind, has to feed twenty mouths with his personal reputation, and doesn’t allow endless waiting. Re-running elections is the king.

I would remain cautious. You are giving up the fixed price of 5.5k. What is stopping the contractor from demanding another 50k?

Or have I missed something?

I want to quote this here again so it doesn't get lost!

If it is only this change, then it could really open the door for just about any subsequent increase!

If this is the only change, then it could really open the door wide for just about any subsequent increase!

Help me, where I might have overlooked it: in what way do you see the acceptance of the new offer price "previous price + 5.5k" as a breach of the dam and a blank consent to all future price increase demands, moreover in an unlimited upward amount? The old price was guaranteed in the situation "before construction start" for a "construction start x up to a maximum of 12 months" (so actually still valid for another month currently). The new price, being only a symbolic mosquito bite higher given the current market, therefore no longer requires a new time limitation, since the event "construction start" is no longer affected by the risk of "unknown distance." Without further ado — although admittedly only a technical businessman and not a lawyer — I do not see previous agreements about price adjustment clauses or similar as revoked here and thus still valid unchanged. However, the original poster must here — preferably with legal counsel — clearly distinguish between a merely not legally grounded recognized price increase on the one hand or an independent completely new offer on the other!

Help me, where I might have overlooked it: in what way do you see the acceptance of the new offer price "previous price + 5.5k" as a breach and a blank check approval for all future price increase requests, furthermore with no upper limit?

If only the shown passage changes, this means that it is mentioned just "in passing" in an email or similar that it will probably be around 5.5k. But if this is not defined more precisely, the fixed price commitment is lost for the time being. What price increases are then possible, I cannot say.

If only the shown passage changes, this means that it is only "mentioned in passing" in an email or similar that it will probably be around 5.5k. But if this is not defined more precisely, then the fixed price commitment is lost for the time being.

"By the way" one can say almost anything or nothing in an email, as long as one stays within the framework of the FDGO, as we know from Father Franz. An agreement to a price increase of "let’s see, no guarantee, maybe around 5.5k" can certainly not be made in this way. What matters are the headline and the content of the legally effective document: namely ...

Which price increases are then possible, I cannot say.

... B) how "badly" actually off limits, if it is an independent new offer, regarding which there is only a perceived connection for the OP with what has been discussed before, or else A) how "acceptable", if only the price guarantee is terminated with regard to changes in amount and duration of validity and the old contract otherwise remains in effect (whereby I would consider all those not expressly continued under changed conditions as no longer valid) – that is why consulting a lawyer is recommended, a layperson can quickly underestimate cunning tricks.