I suppose it depends on what activity occurs inside the shed as to whether it accumulates condensation or not. What's wrong with good old-fashioned wood? - at least it allows water vapour through it.
Hi buidersmate, I agree, wood is best but I have a mobility scooter and need the wider door supplied with metal sheds for easier access. I have two wood sheds,...one for working in another for my lawn mower and garden tools and a brick shed which isn`t big enough. It`s a good job I have a large garden.
I have a metal shed, but it was bought from 'Norfolk' the people who supply greenhouses etc. Very happy with it, and no sign of condensation inside. It has double sliding doors with gives good access for garden mower etc. Having said that, it was a devil to put together, but really sturdy when complete, and it is standing on a concrete base. All the pieces were individually numbered, with a matching plan to show how to construct the shed. It's a 13ft x 11ft.