Insulation for a 100mm Stud Wall

[theprinceofdarkness]

I think that the room should also be heated, else when you open the kitchen door a waft of warm wet air willl hit your cold walls and condensation will occur. You have to either make it part of the house or seal it off and vent it , so its "outside". Sounds as though you are making it part of the house, but it has to be just as warm.
Frank

 

[motorbiking]

Not sure if you got what I meant the bottom 150mm of the wall need to be impervious to fluids seeping under the wall from the garage unless the garage floor slopes away at the required fall(sorry can't remember what that is but it is specified in the building regs)
Have a look on the celotex site, they have a u-value calculator, but for a garage divide, with plasterboard on both sides I'm pretty sure that 60mm between and 25mm over the studs will achieve the correct u-value.

my 150mm was a reply to the OP. I.e how much rockwool type insulation he'd need to hit the U Value.

you could do it with double plaster board both sides a 70mm celotex.[/QUOTE]