Just scrapped a metal `garden store` because of the condensation problem, that and it was never very weatherproof due to the flimsy construction and poorly aligning parts.

Current workshop is brick with asbestos cement roofing, more cement than asbestos one of the neighbours had it analyzed for employers liability, lined internally in shuttering ply, its heatable and a small heater running 24/7 keeps the damp at bay.

Used to be across lane, its a lane of workshops of varying sizes, that had same roofing but no lining, on a cold day it rained inside,more than one person in, it rained more. On a hot day needed the doors wide open and fan running , without them open could probably bake bread.

Cheers
Adam