Kitchen floor insulation? New 2007 build

[Andehh]

For a kitchen & dining room knock through we are looking at wet underfloor heating for it. Approx 30sqm in total.

The house is a relative new build (2007 Bryant home) , and when we had the lounge carpets replaced found a concrete/screed(?) floor under it.

Now, with wet underfloor heating require a decent insulation under it, I am keen to find out whether this concrete floor will be insulated itself, or whether we would need the recommended 80-odd mm of insulation on top of the concrete/screed(?)?

Can anyone suggest the current insulation values of the floor? And what would be required for wet underfloor heating to work effectively?

Thanks

edit; correct room size updated.

 

[Newboy]

I think that the U value for floors was 0.35, now 0.25

 

[Andehh]

Thanks mate, does anyone know what the insulation requirement is for underfloor heating to be viable? i would probably be able to get 25mm insulation on top of the concrete, but wouldn't be able to add much more depth then that.

Cheers