And yes, 100mm internal is overkill. 25-45 is plenty.Weirdly enough I'll be doing almost the exact same thing as Xeres at some point in the new year. Well, in a mid rather than end terrace and with the back of the house needing a new render too. Not too far from Lancaster either, small world...
My initial guess was to go 100mm thick with external render at the back, then 25mm internally. Then just 100mm internally at the front, is that ridiculous?
For the internal without external contact I didn't realise that Bauwer light would be needed, what's the need for an insulated plaster on internal walls? It's already going to be a decent sized job, potentially the whole house 110m2 of floor space maybe 300m2 of wall space (at a guesstimate), I was hoping for something a bit cheaper for the internal walls without external contact!
Apologies for sniping into this thread!
And yes, 100mm internal is overkill. 25-45 is plenty.
Cheers for this. To confirm though:
For internal walls, say from the front room to the back room downstairs, I'd expect the whole floor to be more or less the same temperature so it doesn't matter if the walls conduct heat right? For the internal walls between this and the neighbours houses some insulation would be useful but, typically, the temperature gradient would be lower so it's less important. Especially if they're rich boomers who leave the heating on all the time, I'd be better off nicking their heat through the walls then!
For the thickness, I'd thought 100mm internal at the front as there's no external insulation there. It's just to get the u value down based on Bauwer's calculator. Aiming for 0.7 needs 70mm plus. Is that just a case of whether I think it's worth the extra install cost/hassle for the extra insulation? I.e. from your perspective it doesn't really matter if it is 25 or 100 or does it make it more difficult in general to put on?