Sole insulation - heating cost savings

Hello,

I am building a 127 sqm bungalow with gas + solar + underfloor heating.

A 20 cm reinforced concrete slab with conventional insulation under the screed is planned.

An additional perimeter insulation under the base slab costs about 2,500 euros.

The architect has calculated additional annual costs of 40 euros with current energy prices without extra insulation.

What are your experiences here? How much heat is actually lost in reality? Maybe some of you have experience?

Thank you all in advance.

How is someone supposed to have experience? No one has the exact same house twice except for the basement insulation

If your architect says that, why don’t you believe him? Sounds very reasonable... good architect

Are you building without a basement? How thick would the insulation be?

With those figures, the answer would be clear to me.

How is someone supposed to have experience? No one has the exact same house twice except for the floor insulation

If your architect says that, why don’t you believe him? Sounds very reasonable... good architect

Because the costs were mentioned independently of the energy source or type and he otherwise didn’t present himself particularly well.

I’m actually only interested in whether anyone here has installed underfloor heating without under-slab insulation in a new building and whether the energy costs remain manageable over the winter or if there is an unusually high additional consumption. I am already aware that a 1:1 comparison here is not possible...

I, but no experience yet. And you won't really notice it - especially because you have no comparison. And the costs will quite certainly not skyrocket.

Are you building without a basement? How thick will the insulation be?

With these numbers, the answer is clear to me.

Exactly, without a basement. Masonry of the base slab with calcium silicate bricks with perimeter insulation in the edge area of the slab. I will find out on Friday which insulation will be installed under the screed.