I have some disused stables that are available for storage. No horses please!
Each unit is 12x12m, they are prone to some condensation and therefore would only be suitable for non- electrical tools spare parts or anything that doesn't mind a bit of damp. No soft furnishings.
Would suit a trades person
Each has top and bottom stable doors, where you can easily secure with a padlock and they are in a secure site where I live and therefore are watched 24/7.