Apply Kingspan to the EXTERIOR of house?

[Andy Wade]

No it doesn't actually. The 'thermal mass' - strictly thermal capacity, i.e. mass times specific heat - of the masonry isn't affected by adding insulation. OK, the insulation itself has some thermal mass, but that will usually be negligible in comparison to the mass of whatever's being insulated.

- it turns the masonry into a heat reservoir

What you're trying to say is that it increases the thermal /time constant/.

Time constant of a structure = (mass * specific heat) / (U-value * area)

(First-order system approximation.)

[normanwisdom]

Yes but it's useful performance as a thermal mass has value if insulated on the outside , so there tit head

[Andy Hall]

That rather depends on whether one *wants* thermal mass.

The other side of that coin is what happens if the weather changes and temperature changes?

If you have high thermal mass to contend with then it will take longer to address the effects of that.

Storage heaters and underfloor heating are examples of that. The former are worthless and the latter need careful operation.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Doctor Drivel" saying something like:

Bad day for reading comprehension, is it? He quotes that as being the type of thing that's said by the ignorant.

[Doctor Drivel]

Matt, you must understand thermal mass and its benefits. Buy "The Whole House Book".

The heating system adjust to suit. Matt, you really don't know.

[Andy Hall]

I didn't say don't do it. I said understand the implications.

[Doctor Drivel]

Matt, you still don't know.

[Andy Wade]

Actually in well-insulated buildings with long thermal time constants (achieved through the use of high thermal mass) they can work very well.

[Andy Hall]

Not many of those though...