detached 4 unit modular metal building. The city would have required fire walls had there been electricity or gas. Again, it does make money, but sometimes it is a lot of bullshit to get your $50 bill. Also check your state laws for storage units and how they want the contents handled after non payment. Auctions are sometimes required. I've been fortunate to keep three units occupied by the tenants in the apartments. I had the fourth one rented, but I ended up keeping it last time for my maintenance junk for the property... Mower, snowblower, ladder, wheel barrow, etc... It allows me to ride my bike to the rental and do most maintenance. I ended up making more money this way than renting it. It mostly makes my apartments a better value proposition and raises the rent $50. The tenants like them. I would never go into the mini storage business though.