In my head, i thought some non-flammable insulation in the framing, followed by a vapour barrier and then cedar/larch/pine cladding would work well to be reasonably insulated and mean heat-up speeds were good. I'd imagine that'd make sense for a basement too (depending how outdoor-ey your basement is).
Yeah - there were quite a few, this made sense to me: https://www.saunafin.com/blog/sauna-kits/how-to-build-sauna-kit-guide/
This guy's recent video looks pretty helpful for the actual build up - https://www.youtube.com/watch?v=J7Cj9q00nJA&ab_channel=JohnThain
In my head, i thought some non-flammable insulation in the framing, followed by a vapour barrier and then cedar/larch/pine cladding would work well to be reasonably insulated and mean heat-up speeds were good. I'd imagine that'd make sense for a basement too (depending how outdoor-ey your basement is).