our house is solidly built with masonry at the bottom and timber frame construction at the top. The walls downstairs are insulated from the inside; a composite panel with adhesive blobs was simply glued to the wall. So drywall (yuck) with 3 cm of styrofoam. It’s super easy to run cables inside, so all cables in our house are laid on the walls and underneath these composite panels. There is some air space between the panel and the wall because of the blobs. With this type of internal insulation, you definitely have to make sure that the insulation is not bypassed by air, so everything must be sealed airtight; for this, surface bonding is better suited than blobs. Because if air gets into the gap and cools down there, mold can develop. Otherwise, I find this kind of internal insulation very well suited to prevent mold, because there are no more cold corners. Our house was unoccupied and unheated for 1 year; the lower floor is still unheated now and has about 14-15° C in winter, and we ventilate very little, at most once a day, and there is no mold anywhere. So you can definitely do it this way if you pay attention to airtightness.
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