Subsequent structural change/costs

The exchange from wood to concrete has the "disadvantage" that the concrete staircase needs to be covered. The costs will presumably be added on top once you get to the topic of tiles/floor coverings ...

The change fee just for the redesign at the entrance and exit is symbolic (or as Monaco Franze would have said: "more psychological, you know?") – thus overall this is a bargain price. Not to mention that according to the principle "perverse costs extra," a downgrade to a concrete staircase should be much more expensive *LOL*

The static calculations and especially necessary changes required due to client requests cannot yet be known concretely at the time of the offer creation. Especially since the mentioned additional cost is really reasonable. I hope the €1000 hasn't eaten into your buffer now; you will need significantly more of it. The switch from wood to concrete has the "disadvantage" that the concrete staircase will need to be covered. The costs will probably come on top as soon as you get to the topic of tiles/floor coverings ...

These client requests were known at the time of the offer creation and were indeed taken into account, but only partially. And that is, in my opinion, the striking part. They calculate the staircase change down to the last cent, but the statically necessary changes that go along with it (and cost thousands of euros) are omitted/forgotten. This is with a house-building company that has planned and built hundreds of houses. Sorry, but at this point, you can no longer believe in coincidence.

PS: The amount of the price for the ceiling widening is certainly justified and we do not question it. PS2: We are aware that additional services will arise for the concrete stair steps and have factored this in. We have no problem paying money for services. But paying money for mistakes in the offer creation—that diminishes the interest.

These client wishes were known at the time of the offer preparation and were taken into account, but only partially. And that is, in my opinion, the striking point. They calculate the staircase change down to the last cent, but the statically necessary changes that come with it (and cost thousands of euros) are omitted/forgotten. This from a house building company that has planned and built hundreds of houses. Sorry, but you can no longer believe in coincidence.

PS: The price level for the ceiling widening is certainly justified and we do not question that either.
PS2: We are aware that additional services for the concrete stair steps will arise and have factored that in. We have no problem paying money for services. But paying money for mistakes made during the offer preparation, that diminishes the interest.

But you signed a legal contract that says everything about the statics. You would then have had to agree on a fixed price there.

We have no problem paying for services. But paying for mistakes made in the quotation process, that’s where the interest fades.

Where exactly did it say in the offer that the change fee also included the whole constructional and technical planning rat's tail behind it??? Do you seriously expect that just for two green ones, the stair order, the stair execution drawings and the structural calculations are to be changed and on top of that there is an extra 1 cubic meter of concrete per 25 sqm ceiling (not to mention the changed reinforcements) as a customer service bonus? What you have to fork out overall is already a special price in the concrete stairs promotional week!

If you call the additional charge that way, a layperson is allowed to accept it, right?
I think it's asking too much for a layperson to determine whether that is a realistic surcharge.

We signed a construction contract with a guaranteed fixed lump sum price. After the ground floor ceiling was in place, the contractor said that massive walls with concrete beams had to be installed in the attic due to structural requirements, because the roof structure could not rest on the planned drywall partitions. Additional costs approximately €6,000. We said that this could not be our problem since we had agreed on a guaranteed fixed lump sum price. There were also other disagreements and significant defects, so this additional claim was the last straw. The result was that he stopped the work and cleared the construction site, we filed a lawsuit, he agreed to a settlement, and after 10 months is now continuing construction. In total, we had about €20,000 in court and lawyer fees, which the contractor now has to reimburse us except for the settlement costs, but it could have had a different outcome.