Perimeter insulation under the floor slab and still XPS under the screed?

Yes, I am familiar with a Schwedenplatte. However, I find it hard to come to terms with the idea that the weight of my house rests entirely on thermal insulation.

Good morning,

I am bringing up this "old" topic again because we are currently facing the same question.

I am not concerned about the full weight on the insulation; it has been tested many times and proven effective.

Our construction starts around the end of March. We do not have to, but we have the option to additionally insulate the floor slab.

Cost for just over 100 sqm is about 2300€.

The energy consultant remains noncommittal. Calculations show that, in his opinion, we will not recoup the additional costs within the next 20 years.

Basically, I am open to such things – since you really can't get to it later – so now or never.

The "only" advantage is the higher efficiency of the underfloor heating?

The "only" disadvantage is the additional costs?

I would be glad if someone has an opinion or would share their experiences with us.

Hello,

I have decided against it after all!
But I also have XPS insulation of I believe 18cm under the stapler plate of the underfloor heating.
I was simply put off by the additional costs and the increased extra effort and the fact that you never get the money back.

Regards

I honestly can't exactly say why I tend to lean towards it rather than against it. I don't want to skimp on the wrong end. Are there any other aspects besides a small heating cost saving that speak in favor? Maybe someone else has decided for it and can tell me why

A negative reason would also be the relocation of the grounding under the floor slab. This then has to be done differently because the insulation must not be damaged.

That does not matter to me because it is the responsibility of the BUs. They do this regularly, know what they are doing, and the price includes the effort.

I only have to evaluate cost/benefit (want).