Is the construction of the basement wall or floor okay like this?

Hello everyone,

we are in the final stages of our house planning (which has been dragging on for two years now...), but we are about to finally submit the building application!

Now I have received detailed plans from the architect and am unsure about the construction of the basement walls and floor. Specifically, my concern is that for the walls the insulation is on the outside and then comes the concrete, whereas for the floor, the concrete slab comes first and then the insulation. Although insulating blocks are planned, doesn’t that create a thermal bridge directly into the basement?

Attached is a picture.

That is a kind of black tank, right?

Even though this is the basement subforum, is the roof construction okay like this?

Thank you very much in advance!

The roof can be done like this. Whether the 28 cm rafters are statically necessary cannot be said like this. In any case, that seems very much to me.

Why is the support span on the ground floor so large? A 30 cm beam layer is quite expensive. It can be done much cheaper with something like this.



A no-go is the ceiling height of 2.36 m.

Now I have received detailed plans from the architect and am unsure about the construction of the basement walls and the floor. Specifically, my concern is that for the walls the insulation is on the outside followed by the concrete, whereas for the floor the concrete slab comes first and then the insulation. Although insulating bricks are planned, doesn't that create a thermal bridge into the basement?

According to the text description, 6 cm of "pressure-resistant insulation" is to be placed under the floor slab. Therefore, this is not initially so problematic, but the thickness is ridiculous – at least 14 cm should be provided there (depending on the energy ambitions, considerably more). I hope the note "clean concrete" between the floor slab and insulation is a typo – it must be placed under the insulation.

Make sure that the front edges of the floor slab are also properly insulated; according to the drawing, they are currently not insulated (although the floor slab is depicted very oddly) – that means the insulation must be against the front edges and also from above (possibly wedge-shaped) connected to the wall insulation.

For this, the PUR insulation above the floor slab could be made somewhat thinner (e.g., 60 mm, if the installations allow this) – this could gain 4 cm of room height.

I find 12 cm of wall insulation very optimistic as well – more would be better.

As mentioned, insulation is also planned under the ground slab. 12 cm PU against the cellar floor + 6 cm XPS (probably) underneath are also good. 12 cm PU have a WLG of 022 and against soil this is absolutely sufficient. The 10/12 cm against soil on the cellar wall are also sufficient according to the Building Energy Act if it is 036 XPS. Better performance with the same insulation thickness is possible with 027 Resol rigid foam, but it is just more expensive. The roof should be good with 28 cm beams and accordingly thick insulation for thermal protection, as well as the stud walls.

Why do you actually extend the ground floor so far above the original terrain level, especially since it is sloped on both sides?

we are in the final stages of our house planning (which has now been going on for two years...), but are about to finally submit the building application!

All the more regrettable do I find it that you no longer involved us in this, after your concept has apparently changed significantly since ... and now only on one problematic point, instead of showing the whole house :-(