That's a zoning question, and the answer varies by location. Most Michigan townships don't allow accessory structures to be used as full-time residences without meeting specific building code requirements for habitable space: plumbing, electrical, egress windows, minimum square footage, and more.
Some municipalities are loosening rules around ADUs, accessory dwelling units, but it's far from universal. If full-time living is your goal, talk to your township before anything else. They'll tell you what's allowed and what modifications would be required.
Our buildings make excellent guest spaces, seasonal retreats, and supplemental living areas. Whether they qualify as a legal dwelling depends entirely on your local codes.
