I know its not spec, but I think it should be okay -- even though the wall is drywall, I think the distance is enough to not worry about the paper/cardboard sheathing combusting - and as far as I know the gypsum itself is non-combustible, and there there is absolutely no wood studding or framing behind -- that's all metal ... and the floor is granite porcelain tile, plus the base under the stove is 15 cm thick dolomite copping stones from demolition of a very old building in Jersualem - so nothing combustible there ... where the flue hits the wood ceiling and through to above the roof is a double walled fully insulated sleeve that was custom fabricated for the job, and the transition to class A flue takes place a good 25 cm before it even approaches that sleeve, so everything up above looks good -- so no shortcuts there ... I spoke to both the installer and the stove dealer this morning and both felt 100% about the situation -- and overall they have seemed trustworthy to me ...