My construction dude told me to apply 6x6 cm squared timber for installation (electricity) and spread the about 30 cm apart from each other around the house. Once the electrician comes and installs everything and is finished I can install plasterboard onto the 6x6cm squared timber.
I am just not sure if I can hang anything on the plasterboard that is attached to 6x6cm timber. It would be alot more stable if I could get rid of the 6x6cm timber and attach plasterboard to plywood (like the inside walls).
At the end he said it’s for electricity only and my safety so I don’t break the vapor barrier later if I screw something into the plasterboard. So I have about 6 cm “air” before the “real” wall starts after the plywood.
Its basically from inside to outside:
Plasterboard -> 6x6 cm squared timber -> Plywood -> Studs -> Vapor Barrier -> Insulation (240mm wool) ->… in the end the totall wall is about 39cm thick.