Assessment of the offer price for insulation under the floor slab

Thermal protection verification and static calculations are not required from us for the building permit. However, they must be submitted before the start of construction.

Here in NRW it's the same. But it's nonsense to request a shell construction if you have no specifications for insulation thicknesses. Wrong order. Sounds like a layperson is playing architect here.

We plan and award the trades ourselves. What do you mean by wrong order? I choose a builder and the planner/structural engineer of the builder then creates the submission plan/thermal insulation certificate/fire protection, etc. If I have a house built with Schlagmann T8 bricks and a concrete ceiling, the builder will know from experience which insulation must be at least under the floor slab.

You write about shell construction, now let's say it is a contractor who is also supposed to provide planning services. In the next sentence, it then says you award the trades yourself....

Once again, good luck. ;-)
You will need it.

It can roughly estimate what needs to go under the foundation slab. However, the thermal insulation verification today is a bit more than T8 + foundation slab = Energy Saving Ordinance. Not just one part is considered alone, but the house as a whole. Type of heating, windows, ventilation, ...?

I already know the procedure. The master mason does the input planning and you do the rest yourself. This used to be standard for us, but since the trades are increasingly interconnected, this approach is becoming more difficult.

We plan and award the trades ourselves. What do you mean by wrong sequence? I choose a contractor and the contractor’s planner/structural engineer then prepares the submission plan/thermal insulation certificate/fire protection, etc. If I have a house built with Schlagmann T8 bricks and a concrete ceiling, the contractor will know from experience what insulation at least has to be placed under the floor slab.

What is your architect or draftsman doing? He has to define everything holistically. It won’t work with the current approach.