The main house and the completed rear extension is block built and so we planned on continuing this in the side/over roof extension. The front and the side of the garage will be getting demolished as we extend out from there and rebuild the gable end in cavity block.
I have attached some detail the architect has provided on how the space should be constructed. He has stated that as the garage space is unheated then there should be no insulation in the newly created gable end wall. He hasn't shown this in the drawings but that then means the cavity wall in the bedroom then has no insulation in the cavity and that he has just used insulated plasterboard on the bedroom internal wall.
Is there not a better way of doing this?
There will be no heating in the garage but I am planning on using the garage as a gym/workshop so should I just insulate that whole wall??
My other thoughts were would it not be better to just have a timber frame above the garage which would then allow the frame to be properly insulated but only for the upstairs still leaving the garage space not insulated?