Hello everyone.
We are renovating a house from the early 1900s. We are now thinking of insulating the outer walls and also the inner walls.
The crux is, or maybe it's just me being a big amateur and not understanding, but the designer who planned the layout didn't include any air gap? Neither on the inside nor the outside.
I talked to my contractor who said they would put a 20mm air gap on the inside instead.
Am I completely off track here, or shouldn't there be one on the outside?
The wall consists of some old stone-cement, a bit unclear but I'll attach a picture of it, and it's about 400mm thick. The yellow facade brick has come down so we don't need to think about it.
Any help would be worth its weight in gold!