Dense Blocks used - is insulated plasterboard a must???

[^woody^]

than your brute force, line everything on sight solution

A typical builder's way of thinking

Yeah, but how good are you at arm wrestling eh Woodpulp?

Lol. Not as good as I am at sprinting

Oh that comment sounded bad. What I meant was that the OP has a design problem which has a design solution .... which would be better than the builder just adding more layers of insulation

 

[theoldun]

What I meant was that the OP has a design problem which has a design solution

Well, we agree on at least one thing woodenhead, the OP has a design problem, so in all your wisdom, could you please put one of your funny hats on, put your money where your north and south is and kindly tell us the design solution.
Regards oldun

 

[^woody^]

Its as mikric has already pointed out - a SAP calculation for elemental trade-off or whole house trade-off.

I'm not going to do it for the OP, but at least now he knows that there is another option to explore

 

[bregsadvisor123]

Scottish Building Regs are not the same as England and Wales. U value of extension walls will require to be 0.19 or 0.22 dependant on the existing building structure.

 

[daveb789]

Have all your other elements of insulation been installed ie floor/roof etc ?
If your not to bad at maths/areas etc a notional building trade off calculation for an extension is relatively simple to do and you might get away with increasing insulation u-values elsewhere in the build. If you want to have a go just shout and I will try and explain how to do the calculation.

Hi mikric,
Thanks for your post, I have not yet installed floor or roof insulation, I was hoping this solution may be an option, as on posting this problem I did hope I could overspec roof insulation to compensate.
Would very much appreciate any help with calculating such a trade off to propose alt. solution to buiding control.
Thanks.