I want to build a shed with moderate insulation; I was thinking of 95 or possibly 120 mm. The wall would then be, for example, 12+95+11+12 = 130 mm thick, plus a ventilated facade construction. I don't want to place the wall directly on the slab but have a plinth somewhere between 300 and 800 mm high, and it should also be insulated, although it will likely have to be thinner, say 50 mm, but preferably more; the plinth shouldn't be thicker than the wall. The insulation should mostly be on the cold side of the plinth. Many would build with concrete blocks or lightweight concrete, but these are not particularly efficient insulation materials. Perhaps a plinth could be built with metal studs, but I am interested in a rather high and partially earth-covered plinth, and in that case, concrete seems like the best option.
What do you others on the forum think would be the best solution in such a case? Some kind of sandwich plinth with insulation somewhat inside the center? Relatively thin concrete plinth with insulation and some kind of board on the outside? How do you ensure that the wall sill has sufficient support in the latter case?
Residential houses are built today with thick insulation, and it is generally affordable to incorporate both load-bearing and insulating functions in the wall and plinth, but for plinths with thinner walls where you also want to manage contact with damp soil, it seems like a challenge.
