Off-Grid Living in St. Clair County, Michigan

St. Clair County, Michigan is one of those places where the answer to "can I live off-grid here?" really depends on which of the 22 townships, cities, or villages your parcel sits in, because the county itself has no countywide zoning ordinance. I want to be upfront about that structure before anything else, since it changes how you research your specific property.

Zoning is handled entirely at the local level, each township or city (Riley Township, Grant Township, St. Clair Township, City of St. Clair, and so on) writes and enforces its own zoning ordinance, with its own Planning Commission and Zoning Board of Appeals. The county's Metropolitan Planning Commission plays a coordinating role, but it doesn't override local control. That means minimum lot sizes, whether you can occupy raw land, and rules for accessory dwellings all vary by jurisdiction. There's no substitute for pulling up the actual ordinance for your township on Municode or calling the local zoning office.

Dwellings, tiny homes, and RVs run into the same local patchwork. I found at least one municipality's code that sets a minimum dwelling width (twenty feet across any elevation) and minimum square footage, tied to the Michigan State Construction Code Commission's standards. That's a real hurdle for tiny homes on wheels or small manufactured structures used as permanent residences, and RVs as full-time housing generally aren't given a favorable carve-out. Confirm with your specific township.

Building permits are also local. City and township building departments enforce the state-adopted construction codes (Michigan Bureau of Construction Codes sets the underlying code text), but there's no single county building department, so permitting authority, forms, and inspection schedules will differ depending on where you build.

Where the county does step in uniformly is environmental health. The St. Clair County Health Department's Environmental Health Division issues sewage/septic permits countywide, before you install or repair a system, and also handles well permits, site reviews, and drinking-water oversight. Composting toilets as a stand-alone legal substitute for a permitted septic system aren't addressed in what I found, so that's an open question worth asking the Health Department directly.

Greywater and rainwater harvesting have no county-specific rules that I could locate, so both fall back to the Michigan state plumbing/residential code baseline (rainwater harvesting is generally allowed under state code; greywater rules are less clearly spelled out and worth double-checking with the state or county directly).

Wells are permitted through the same county Health Department, with the state's EGLE playing an oversight role at the district level (St. Clair County is covered by the district that also serves Macomb, Oakland, and Wayne counties).

Full utility disconnection isn't explicitly banned or addressed in any county source I found, but since septic and well permits are effectively mandatory to get a residence approved, going fully off-grid on water and waste still means going through the county's permitting process, even if you're skipping the electric grid.