Is base plaster not part of a house?

A lot was also missing in the description of construction services on our part. I made a list of what we want included, which came to almost 2 pages. Showed it to the company, either like this or not at all. It was accepted and included as an additional agreement in the contract. A few thousand euros added up there, which would have come back to haunt us later. Surely I must have overlooked something, but I think that by reading and thinking more carefully, a lot of trouble can be avoided.

You are both right. And still, I see a duty to advise in the BU. Imagine your wife wants a dryer. You have absolutely no experience. Amazon, lowest price first, vented dryer Beko, 199,-. Cool, you think, why burn 699,- for Bosch when 199,- will do. That’s enough for our towels....You go with the same intention to an electronics store. Again, this price difference. You say to the salesman, we’ll take the one for 199,- He should now make you aware that for the cheap one you need a wall breakthrough to lead the vent hose outside. Oh, you think then.... We don’t have that. Then it just won’t work....Karsten

The BU wants to make money from the fact that it wasn’t noticed beforehand.

Later on, they then calculate exorbitant prices for that.
And since you can’t get another company for that at that moment, unfortunately you pay it.
In the end, it’s a kind of rip-off, but as already said, anyone who spends that much money should make the effort to read properly.

You are both right. And yet I see a duty to advise with disability insurance.
Imagine your wife wants a dryer. You have no experience at all. Amazon, lowest price first, vented dryer Beko, 199,-. Cool, you think, why burn 699,- for Bosch when 199,- also works. That’s enough for our towels... You go to an electronics store with the same intention. Again this price difference. You tell the salesman, we’ll take the one for 199,-. He should then point out to you that for the cheap one you need a wall breakthrough to lead the vent hose outside. Oh, you think then... we don’t have that. Then it can’t work at all... Karsten

Your example is of very low complexity. The devices only differ by a handful of key performance features; whether vented or condenser is prominently stated in the product description. As a liberal person, I believe everyone should be able to understand this with their own intellectual capacity.

Building a house is a highly complex project, an expensive one at that. For the average person, by far the most expensive thing in life. Why approach this so naively like buying a dryer? I lack sympathy for that. One gets the impression that the Golf car’s special equipment catalog is studied (and researched) longer than a construction scope description.

I myself sat down with a single general contractor (you want to have a comparison to architect-built) and was surprised how extensive his cost breakdown for construction-side services was. Almost (subjectively) complete, I mean only the construction cost surcharges for house connections were missing (though those are always uncertain but can be a hefty amount). I found that quite good and also reassuring, even though I felt some items were estimated too low.
He was also not a cheapie, close to the architect’s cost estimate submitted. Whether Town & Country or Danwood set reasonable flat rates for external works or painting, I do not know.

Here it was more based on trust. There was a construction service description and there was a very realistic cost breakdown for what normally comes as extra when you have companies do it. And there was the offer of the BU to gladly name companies for this. To mediate. But there was a rather short construction service description. So I asked: Mr. S., is everything included? Much is not very defined. Does the tiler do the silicone joints, for example? etc. His answer: Then we could write a little book as a construction service description. No, trust me, everything that belongs to a house is included. So that you can move in, live in, and use it. Ok, I agreed to that. Karsten

Well, things usually don’t go the way they do with you. Who knows their future construction company beforehand? For example, I had the contract and the construction service description checked by a lawyer and an expert through [Bauherren-Schutzbund] (about 600€) and then agreed on an eight-page special service list with the (small) general contractor. Now, everything is probably fixed 99%. What was quite surprising: the necessary additional earthworks included. Disposal, about 12k. I hadn’t considered that beforehand. But it made sense; the civil engineer had good ideas and advice regarding level alignment with neighboring properties; in the [Thüringer Wald], there are always some height differences ... :-) Up north with you, it’s usually pretty flat, right?
In spring, we’ll see if everything was consistent.

The argument is always that the GU base cannot know how the surroundings will be designed. Will there be paving, a gravel strip, terrain height, protection, stud membrane, sealing slurry ....

Partly probably correct, but annoying if it is overlooked in the construction specifications.