Tim Lamb wrote:

One difficultyÂ* we discovered with a refurb and planned underfloor
heating throughout is adequate insulation over solid floor slab.

UFH for a refurb is obviously more difficult than a new build, from what
I can remember it's mostly(?) the new bits of Adam's site have UFH and
hopefully decent insulation under, the old bits have radiators, but it
looked like a rat's nest in the corridors.