ARWadworth wrote:
My brother will be starting an extension soon and he is considering
underfloor CH? Is it really as good as it claims to be?

I see various problems. The extension will be a bedroom with an ensuite
over his attatched garage.

1. He will be heating up the floorboards and probably a carpet before he
gets any heat, that must be a massive waste of energy. Would a good
quality wooden floor be better than a carpet?


It not a waste of energy, it is just a time delay. Conversely the heat
in these will stay there after the heating goes off. A massive saving in
energy :-)


The key is to make the path to the cold places a lot better insulated
than the path to the places you want to heat! I.e. LOTS of insulation
under the pipes.



2. Would I need to zone off the bedroom and ensuite seperately? I will
zone them off from the rest of the house regardless.


Maybe. One tends to have sones anyway as all [pipes should be laid back
to a manifold. Its possible to e.g. put a TRV on a small zone.

3. One thing we have considered is making the ensuite floor lower than
the bedroom floor so that UFH could be laid in a tiled screed above the
floorboards and it's finished level would be the same as the bedroom. Is
that feasible?

definitely.

But beware of massive screeds on a suspended wooden structure. I would
rather go for a very stiff wood structure, with kingspan under the floor
and pipes just laid on top of that, and ply over. Then tile the ply.
Make that floor a lot stiffer than you would for carpet or
laminate..maybe 7" deep with herringbone braces..then there is plenty of
room for insulation and pipes as well.



Adam