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 - in
other words acting as a constant heatsink - straight into the ground?

Jim
some, but you need a bit of integral calculus to calculate it..