uninsulated basement = wet basement?

Thank you for the background explanation. I also have the impression that this developer is trying to stay significantly below the competitor’s price. Which also succeeds through less good equipment in the standard package.

I imagine the insulation of the basement as a special request. Ideally even a central controlled residential ventilation system, but I fear the developer or general contractor will not agree to that.

My approximate calculations:
Perimeter insulation of the basement walls: €7000
Complete insulation of the basement floor: €3000 (internal insulation, since with a shared floor slab probably nothing else will be possible)
Controlled residential ventilation system: €10,000

Is this realistic?

I am not yet quite sure about the necessity of the basement floor insulation (regarding moisture in the basement).
Or only the later usable room will be insulated on the floor, the technical and storage room only on the outer walls. Could thermal bridges with condensation risk again arise from this, or would that be okay?
I will also discuss this with the later construction supervisor, but I would appreciate hints from you.

Regarding the new post from W. Pickartz:

The sales advisor told me during the conversation that this is a clearly preliminary building specification. They have only started now so that the deadline for the Kfw70 funding would not become too tight. Otherwise, everything would have initially been finalized in early January and a proper building specification created.

Regards
Ricardo

A genuine salesman, every means of pressure..

My approximate calculations:
Perimeter insulation of the basement walls: €7000
Complete insulation of the basement floor: €3000 (internal insulation, since with a common slab probably nothing else will be possible)

Prices way too high - even if you do no own work. In EL (material only) I paid €1200 for 10 cm perimeter insulation of the exterior basement walls. For screed insulation in PUR (most expensive insulation) it will also be about €1200.

Just as a reference - even with paid workers and a bit of profit, these prices would already be very ambitious.

But of course nice to factor in as a buffer .

Hello Sebastian,
thank you for the assessment - that gives encouragement!

I can also well imagine installing the perimeter insulation myself. However, I don’t know if the builder will agree to that. After all, it would probably take me two or three days. And during that time, he can’t work on the outside.
Besides, I would have concerns about the warranty. I wouldn’t want it to be said later, if water gets in, that we did something ourselves on the outside of the basement wall.

Are there any indications whether it could cause problems to insulate only one of the basement rooms with screed insulation and to insulate the others only on the walls?

Best regards
Ricardo

You can install the perimeter insulation with two people in one day - comfortably. There can be no leaks since you only place panels in front or fix them with bitumen. That’s why we did it that way, but the building waterproofing including the fillet was done by the shell builder beforehand.

Therefore, I don’t see any warranty traps there for now...

I would insulate all rooms with screed insulation - it is possible. There is no frost in the depth... but you always have edge areas that are cooler and extend into the room with the insulation.

I know many who have installed the insulation in the basement themselves. Especially since the basement also needs drying time, it always takes 2-3 weeks when you have time.