Is an offer binding or are deviations allowed?

You’re right ... I would have preferred to avoid it and had offered him that we pay what was agreed upon and no more (so not his high invoice) but he didn’t want that. That was a big mistake because he would have been better off with that, Today the assessor was here and said we shouldn’t pay anything more, the roof was poorly executed and he has to make repairs.

May I ask how expensive the expert was?

well now there's trouble, no one gives in. Keep in mind a craftsman has nothing to give away for free

may I ask how expensive the expert was?

I don't have the invoice yet.... I can tell you as soon as it arrives..... it's simply so outrageous what is going on overall...

Deliver poor workmanship (nail sealing tape is missing and the house is not airtight etc etc) and then want more money?

Send a dunning notice immediately after our first private letter.....

Unbelievable.

I wish you good luck and that you can get the matter done reasonably quickly. Unfortunately, in such cases, both sides usually end up as losers.

I cannot lose, because if I had simply paid his inflated invoice, then I would have lost as well....

Therefore, it can only get better.

But thank you, I will report back