I needed a 5x10 unit and after price shopping around I landed at Alton Self Storage which I reserved for a set price. When I arrived to fill out paperwork and see it there were large pipes in the unit that took up 1.5 feet of space in the back, and then they angled up which cut off about 4 feet of overhead space.
In the storage industry you pay for square footage, it was advertised to have a set amount of square footage for a set price. There were other 5x10 units available, but for the same price OF COURSE NOT they couldn't match the price, that would be RIDICULOUS. Not pleased, but already had a delivery set up for my stuff so I couldn't change our location of storage.
When I was checking out the other person working there stated "Oh I know that unit" and chuckled referring to the piped storage unit. If you and everyone else knew, DON'T ADVERTISE THE DECEPTIVE SIZE SPACE. What you should do is market it at the open available space.