ᐅ Floor structure of basement slab, basement ceiling, and ground floor ceiling

Hello dear forum members,
we are currently in the planning phase while waiting for the building permit / planning permission, and now we are focusing on the planned floor structure. We are building with a basement, and the basement floor is specified by the thermal insulation certificate and should remain as planned. However, we are not completely sure about the intermediate floors to the ground floor and attic. Underfloor heating will be installed everywhere. We are not planning a ventilation system or central vacuum, so only the usual water and electrical pipes will be laid on the concrete slab.

1. Basement slab: Concrete _2400 250mm (10 inches), PS-035 impact sound insulation 140mm (5.5 inches), PE film 0.20mm, cement screed 50mm (2 inches), tiles 15mm (0.6 inches).
Here are my first questions: We originally planned to use self-leveling screed. Does the thermal insulation certificate need to be adjusted for this, or does it not matter which screed is used? Will the self-leveling screed also be installed at a thickness of 50mm (2 inches)?

2. Basement ceiling / ground floor slab, the architect plans: concrete ceiling 200mm (8 inches), floor buildup 180mm (7 inches).
My questions here: What would be an optimal floor structure if we plan tiles almost everywhere on the ground floor as well? Laminate will be installed in the guest room. We are uncertain about the 180mm (7 inches). Isn’t that too much? Wouldn’t a buildup of 150mm (6 inches) also be sufficient? For example: concrete ceiling 200mm (8 inches), impact sound and thermal insulation 85mm (3.3 inches), self-leveling screed with underfloor heating 50mm (2 inches), 15mm (0.6 inches) tiles or laminate.

3. Ground floor ceiling / attic floor slab, the architect plans: concrete ceiling 180mm (7 inches), floor buildup 160mm (6.3 inches).
Here is our proposal for the exact floor structure: concrete ceiling 180mm (7 inches), impact sound and thermal insulation 65mm (2.6 inches), self-leveling screed with underfloor heating 50mm (2 inches), 15mm (0.6 inches) laminate.

And a completely different question: What do you think of cork flooring with underfloor heating?

I would be very glad to receive opinions and suggestions!
Best regards, Kisska86

On the upper floor, the drainage of the shower could be tight if it is to be installed flush with the floor.

A different question: Why don’t you simply have such complex details planned by a professional and, if necessary, explain the reasons for this? No one here can really say what is "optimal" for you—especially considering which aspects. From a financial perspective, for example, a simple construction is "optimal," but probably not from an energy efficiency standpoint.

Good luck

K1300S

@Brata: Thanks for the tip. You probably mean that the insulation is insufficient to properly cover the wastewater pipes? Ok, then using 70-75mm (2.8-3 inches) insulation here would definitely be an option. We just don’t want to insulate too little between the fully heated floors, as that wouldn’t make much sense...

@K1300S: We do consult with professionals as well, but it never hurts to get preliminary information in a forum like this. After all, professionals often tend to recommend what yields them the highest margin rather than what is strictly necessary.

Therefore, I recommend taking a proactive approach and asking questions—after all, the professional must stand behind what they install. In my experience, asking the right questions quickly reveals whether the planning is solid or needs to be revised. Simply telling them what you want may not lead to the best outcome. As a non-expert, I find it highly problematic to try to interfere with building physics in this way. There is an overall concept that cannot have individual details changed arbitrarily without affecting the final result.

Good luck

K1300S

Who do you consider the professional responsible in this case? The screed layer? The plumbing specialist? The architect? Or possibly an energy consultant???