We’ve had a hanson one for a couple of years now, I’ve insulated and lined the inside with osb so can put shelves up anywhere. So far it’s been dry and warm inside, I’ve still got to finish lining the roof but I stupidly filled it up with stuff before finishing so this might take a while.
I had the garage sealed to the base with polysulphide sealant by the company who laid the slab, rather than the mortar recommended by hanson, and fitted a rubber seal under the door there’s no sign of any water penetrating and the sealant has a 10 year guarantee from the installer.
I cheaped out and had timber rather than upvc cladding, I’d recommend going with plastic if you can afford it as the wood needs painting and some of the ply parts are already starting to de-laminate.
The installers were great, turned up on a cold wet January morning and had the thing finished by lunchtime.