How practical / economical is fitting wet UFH under an existing suspended wooden floor?
A friend has just bought a renovated 1900s terrace and is thinking of doing so. He also has a builder about to remove some of the downstairs wall to open up the reception rooms/hallway.
He reckons the upstairs and loft conversion feel warm but downstairs stays quite cool and thinks UFH might improve this.
Does UFH not work best when there's a large thermal mass (i.e. concrete slab)?
In these circumstances, would it improve comfort without necessarily being an improvement economically?