Andy Hall wrote:

I just posted some information on how I did all of this for somebody
asking about heating for an outbuilding. Use Google Groups and
search backa few days.

Andy, I did read your thread and found it very interesting and
informative. I only wish that my outbuilding was near enough to
feed via a new circuit on the CH system... unfortunately, it's
about 250ft away from the house!

My lodge is made from 4x2" tannelised wood, and dressed with
roofing underlay on the walls, with construction cladding over
the top... the roof is WBP 18mm ply with torch-on felt on top
of that... taking into consideration the ventilation gap behind
the celotex, what thickness board could I go for and would I
need to enlarge the cavity by deepening the joists and studs?

Also, do you know of any online suppliers I can get a quote from?

cheers

deano.