On 17 Nov, 22:20, jim wrote:
On 17 Nov, 20:34, "George \(dicegeorge\)"
wrote:

if the insulation is at the outside this is best
as then the walls will be a heat store

but won't there be a huge thermal bridge straight down into the earth
at the bottom of the wall spoliing any meaningful storage of heat

Thinking some more along these lines, what do I do about end walls and
roof insulation?

My specific case (one of several) is the line of small outhouses
pictured in the recent post. There are four of them in a line, the
first three of are single pitched roofs, only four feet wide and up to
14' long. The first is a pantry connected to the inside of the house
(cold and damp), then an outside toilet, then an old boilerhouse.
Beyond that is a workshop, intended for hot working such as welding,
smithing and foundrywork (so not much need for insulation!). My plan
long-term is to convert the outside toilet into a downstairs inside
toilet - obviously this will need decent insulation, particularly for
the roof.

If I'm mostly re-working the roof by adding insulation to the inside
of it, is there much point insulating the outside of the walls, or
should I go for the inside (despite needing every inch of width)? The
end wall is also going to be insulated on the inside, as I've length
to waste and don't want to put insulation materials on the inside
(forge-side) of the smithy building.

Incidentally, I'm also planning a green roof for the smithy, for
looks, noise insulation, and because the existing corrugated asbestos
is simply too low.