Off-Grid Living in Buchanan County, Missouri

I've been digging into what off-grid living actually looks like in Buchanan County, Missouri, and the short version is: this is one of the more regulated rural counties in the state. Unlike a lot of Missouri counties that have never adopted zoning at all under Chapter 64 RSMo, Buchanan County has countywide zoning, and that changes a lot of the calculus for anyone hoping to just buy land and build quietly.

Zoning and building permits. The Buchanan County Planning & Zoning Office administers a county Zoning Order adopted under RSMo 64.510-64.690. That covers all unincorporated parts of the county (cities like St. Joseph and Easton have their own separate codes that override the county's rules inside city limits). Per the county's own ordinance language, a building permit is required for "any structure" in "all zoning districts, regardless of acreage." That's a broad net, it applies to sheds, cabins, additions, and anything else. Build without a permit and the county's ordinance allows the permit fee to be doubled retroactively, and in serious violation cases, demolition. I did not find a formally adopted edition of the IRC or IBC for the unincorporated county the way some neighboring counties (Clay, Boone) have done, so it's not confirmed whether a specific model code applies here, worth asking the Planning & Zoning Office directly.

Tiny homes and RVs. No official minimum square footage or specific RV-as-permanent-residence rule turned up in my research. Mobile homes are handled through conditional use permits issued by the same Planning & Zoning Office. If you're planning a tiny home or converted RV as a full-time dwelling, call the office before you commit to a plan.

Septic. Missouri's DHSS sets statewide minimum standards for onsite wastewater systems, but locally, Buchanan County is one of the counties where the Planning & Zoning Office itself, not a health department, issues septic permits. That office also issues permits for garages, additions, barns and other structures. Composting toilets as an alternative to septic aren't addressed in any official source I found, so that's unclear, ask the county directly.

Greywater and rainwater. Neither Buchanan County nor Missouri state agencies appear to have specific rules on greywater reuse. Rainwater collection looks fine, no local ordinance restricting it turned up, which lines up with the general state baseline.

Wells. Well construction is governed statewide by Missouri DNR's Well Construction Rules. I did not find a Buchanan County-specific well ordinance layered on top.

Utility disconnection. No ordinance bans living off the grid utility-wise, but your structure and wastewater system still need county permits regardless of whether you're hooked to public utilities.

Bottom line: Buchanan County isn't a "no rules" rural county. It has real zoning and permitting teeth, so plan on picking up the phone before you build.