My FiL has just had a summerhouse built in his back garden to put a monster hornby set in, he’s moving it down from his loft. (It’s sold as a log cabin as it’s surprisingly nice/robust but it looks more like a decent summerhouse)

I convinced him to insulate it and he eventually listened. He had the roof and the floor done when it was built, I said I would do the walls for him

The problem is it looks much nicer inside than I thought it would. It’s built using 45mm thick double T&G wooden boards, and the inside finish is actually really nice. I thought it would be more basic so was planning to put celotex/kingspan and then board it out, but it’s definitely not going to look as nice with a board finish as it does currently, even if it was painted

There are no battens to mount it between inside and it’s already double glazed

Any thoughts/ideas/tips on what to do? Given the roof and floor has been done the major bit is done, it’ll be heated gently so it doesn’t get too cold in there when he’s not in it, and then more when he’s in it. Insulation would be good, but I can’t think of a way of doing it neatly without also costing a complete packet

Interior dimensions are about 3.8m by 5.8m, apex is 2.3m high

Fix battens to the walls, staple insulation to the walls in between, nail 12mm T&G cladding to the battens:

Rest of the build.

a mate of mine used broken up pallets to do the inside of his Mancave/shed once he had insulated it, looks interesting and a lot cheaper than T’n’G

@hot_fiat – thanks. that’s probably the ‘nicest’ solution, I reckon it would cost a fair bit but that does give me some ideas