ᐅ Insulation below the slab under the parquet flooring

Hello everyone, my ground slab has a U-value of 0.357 W/m²K.

My questions to the experts:
- How is this U-value assessed for a new build? Is it within an acceptable range?
- What can I do to improve the U-value? The screed will also have insulation added – what do you think about placing additional insulation mats under the parquet flooring? Is that a good idea or unnecessary?

Thank you very much for your answers.

Hello,

VanTide schrieb:

- How should the U-value for a new build be evaluated? Is it within the acceptable range?
- What can I do to improve the U-value? The screed will also have insulation installed – what do you think about adding additional insulation mats under the parquet floor, good idea or unnecessary?

I don’t understand the question. This is about a new build, right? You should be able to find all the information in the planning stage...

Best regards

The question is whether additional insulation is advisable with the above-mentioned U-value.

VanTide schrieb:
The question is whether additional insulation is worthwhile with the specified U-value.

To ask in return: What does the building plan say?
U-value of the foundation slab for the reference building = 0.35 (according to the Energy Saving Ordinance 2009)!!

VanTide schrieb:
... my slab has a U-value of 0.357 W/m2K
- how should this U-value be assessed for a new build? Is it within the acceptable range?

If the requirements of DIN 4108-2 are met, it should be within an acceptable range.
However, in individual cases, further considerations can be useful, such as:
What percentage of the overall transmission heat loss or total energy demand does the slab contribute with this U-value?
There are sometimes misunderstandings here. It is also relevant whether the rooms above are heated or not. Furthermore, underfloor heating requires somewhat better insulation.
More is not always better ;-) but sometimes necessary.

VanTide schrieb:
... - What can I do to improve the U-value?

Reduce the thermal conductivity of the building components layers and/or increase the thickness of the layers.

Best regards.