Many thanks for all of the replies - now off to sort out getting the
wall insulation done.
Whilst I'm on the subject it would seem a good time to take a look at
the roof too. At the moment it is lagged (between the ceiling joists)
with 100mm fibreglass stuff. It seems that todays fashion would indicate
more depth. Or would I be better to add insulation between the roof
purlins under the tiles ?
The roof is a 1980s W wooden frame holding up tiles, with felting
underneath. How I'm going to crawl into the farthest reaches of the roof
space I don't know !
I presume I should leave the small gaps under the eaves open.
What do you think ?