Retrofit underfloor heating into screed and connect it

Good day,

we have the opportunity to buy a house from 1997. I find it very interesting. What bothers us is that it has no underfloor heating.

Now my question. What would such a retrofit cost approximately? Regarding the data. The ground floor is about 65 sqm and upstairs. Bathroom about 12 sqm.

We wanted to renovate the bathroom and guest WC anyway. And on the ground floor I would probably remove the laminate and tiles myself. For more DIY work I lack the experience.

I would appreciate a few answers!

I think no one here can give you a serious answer because no one knows the substance and how the floor structure is. Is there screed in it? Are floorboards installed there? Is there insulation under the screed? Only a specialist company could actually tell you that.

With screed, there is the possibility to mill out the areas for the pipes for the underfloor heating. But that won't be cheap. Furthermore, what supply temperatures does the current heating system operate at? Can it be converted? Would it have to be replaced? That leads to quite a long list of issues.

Year of construction 1997 is somewhat recent. It can be assumed that impact sound insulation and screed are already in place. The easiest way is to remove the old screed, which is not a big issue. (unless it is a timber-frame house)

Insert the underfloor heating pipe, then new cement screed. Cost for the screed approx. €15/sqm including material and installation. (price from a current offer) The heating is uncritical, install a mixer, effort and material approx. €500. It gets interesting with underfloor heating as you don’t know how to get from bottom to top, where to place manifolds, etc.

An alternative would be to use the pipes of an old radiator on each floor, connect a heat exchanger and then connect a compact control station to the heat exchanger, cost approx. €450, and distribute from there. You would need that once per floor and then nothing needs to be changed at the old heating system.

The other radiators could even be left in place...

If I go by the prices currently available to me for underfloor heating, I estimate about €50/sqm fully installed.

All of this is naturally speculative since you don’t really know how it looks. The prices mentioned are prices I have for a current project. However, they always vary depending on the region. So just consider them as a guideline and ask a local craftsman.

Even with timber frame construction, you can remove the screed quite easily as long as it is floating. It worked quite well with our poured asphalt screed on perlite. Once you have a hole, you can happily lever out everything else; the screed was only 40 mm thick, it breaks like warm bread. The question is whether you can find a craftsman at all for so few square meters. Here they refused to come for less than 100 sqm even if we had paid for 100 sqm, they didn't want to do it.