We are planning to build in 2022; the planning begins

I simply assume with this forum that no matter what offer you post, it will be torn apart anyway. You can't please everyone. The most important thing is that we are satisfied and have a good feeling.

I don't read it as if someone is tearing you apart. I believe that they just want to make you sensitive to these things so that you look closely there as well. You now have a good overall feeling and you are proceeding with this provider accordingly. They are not cheating you because of that, but it still makes sense to know such small details and not rely solely on such descriptions. Happy weekend-

You just want every little fart in the forum to be confirmed. You come across as anxious and nervous.

.....which wouldn’t be objectionable, and no one has to read or even respond if they don’t want to. Better for someone to admit uncertainty than to pretend to know while being completely clueless. There are quite a few specimens like that in this world, and I find that far more dangerous.

It's not about keeping the money. Rather, putting the money into the house elsewhere, e.g. upgrading fittings.

I had already understood that. However, you qualify your financing application with usage descriptions that become part of the basis for the loan approval decision. By doing so, you promise to create the collateral value for the money in the form presented. What you describe is the basis for an immediate termination due to the loss of the basis of the contract in the described form as well as due to a profound disturbance of the trust relationship and, in my opinion, also criminal as fraud in conjunction with forgery of documents. You cannot unilaterally dispose of the amounts; the loan application describes a joint project "use of the bank's money for the construction of a specific collateral object." You must not dispose of it in bad faith.

But if I only submit the offer from the general contractor, some things are still missing that can only be priced with the upgrading. Maybe I also have a conceptual error.

You certainly do. Because nobody—not even a banker, not even from Sparkasse Dummsdorf—would seriously set unknown amounts to "0." Realistic estimates belong there. Buffers are needed for something else, namely for unexpected cost increases (for example, if the tilers' guild negotiates an eight-percent wage increase). But I see no sudden additional need on your part for gold-plating the outdoor water tap, or what kind of super worst-case scenario are you expecting in the upgrading?

One primarily hopes for a quick conclusion, because often the number "bottom right" is mainly used as a comparison and decision criterion among several providers.

But a provider would be trading off, winning price-sensitive customers more easily only at the price of them certainly not recommending him to their friends. The reputation one can gain with this clientele depends essentially on the truthfulness of the "number bottom right." That this is "lied like it is printed" can only be afforded by a big name with its inflated advertising department, since such is an indispensable prerequisite for the survival of a brand with the sales method "burn and run." The construction company Jupp Schmitz & Son from the neighboring town cannot proceed this way; otherwise, it would never have come to "& Son."

I would not be satisfied with 35°C flow temperature. Have them offer you 30°C!

Far from heating construction being my specialty, I have the impression that it is not that of the preferred general contractor either. That is why I already recommended to the OP (via PM) to consider outsourcing this trade. A good general contractor does not have to be a universal jack-of-all-trades, and everyone probably has their weak spot.

Sure. But in what amount. I will set a buffer for that.

You only know that after the sample selection. Estimating an amount beforehand can quickly go wrong.

No, here there is a qualified basis from which all wall and floor surfaces can be determined, and a Bauhaus, Hornbach, or OBI leaflet is usually delivered to the door several times a month in a so-called newspaper. There are the square meter prices of the tiles for statutory health insurance patients and for private insured persons, so determining the price delta is not guesswork.

Everyone is entitled to their opinion.

When it comes to comparing the construction service descriptions, I have clearly stated my opinion regarding the mentioned points. I consider them secondary.

What about the electrical program, like sockets per room, network, lighting, outdoor sockets, underground cables, etc.?
What standards are installed in plumbing, and have you actually looked at them in reality? Has a comparison been made with the target equipment?

I would pay significantly more attention to that than to the WU concrete slab or whether someone walks through the house with a thermal camera during handover and usually cannot do anything afterward because the plaster is already applied on the outside. For the other general contractors, the concrete slab will also be statically okay, and water will not press through the floor into the house.

Note: I would not be satisfied with a 35°C flow temperature. Get offered 30°C!

It says something about 28/35 degrees there. But I will clarify that.