Off-Grid Living in Platte County, Missouri

I've spent time digging through Platte County, Missouri's official pages, and the first thing worth flagging is that Platte County is not one of those "no zoning" rural Missouri counties you sometimes read about. It has countywide zoning and adopted building codes for its unincorporated areas, run by the Platte County Planning & Zoning Department. If you're picturing wide-open, no-questions-asked off-grid living here, adjust that picture.

Zoning and raw land. The county operates under the Platte County Zoning Order of 1990, as amended, with an official zoning map covering the unincorporated county. The Planning Commission has jurisdiction outside incorporated towns, so whatever you plan to do with a parcel, check which zone it sits in before you buy or build.

Dwellings, tiny homes, RVs. I could not find a specific minimum dwelling size or tiny-home/RV residency rule on the county's official pages, so this one's genuinely unconfirmed. The general zoning and building permitting process applies to any structure, and incorporated towns like Platte City layer on their own separate code (they use the 2018 International Building Code plus city code). Ask Planning & Zoning directly about tiny homes or RVs as permanent residences.

Building permits. The county has adopted the 2018 International Residential Code and 2018 International Energy Conservation Code, both "as amended," on top of its own Zoning Order and Subdivision Regulations. This is a real, enforced code system, not a rural exemption.

Septic and composting toilets. Before installing any onsite wastewater system, you need a permit from the Platte County Health Department's Environmental Health division, administered under the county's own "Construction Standards for On-Site Sewage Disposal Systems" ordinance. The Platte County Sanitarian issues that permit. I did not find anything specifically addressing composting toilets as an alternative, so confirm with the Health Department directly.

Greywater. Nothing on the county's official sites addresses greywater reuse specifically. That mirrors Missouri's general silence on the topic statewide, but I'd call it unconfirmed rather than assume it's freely permitted.

Rainwater harvesting. No county restriction turned up in my research, so this appears to follow Missouri's general allowance of rainwater collection. I couldn't find a county-specific page confirming it either way, so treat this as inherited-by-default rather than officially blessed.

Wells. Well construction across Missouri, including Platte County, falls under the state's Water Well Drillers Act and DNR's Well Construction Rules, administered by DNR's Missouri Geological Survey. A homeowner can drill their own well without a permit but still has to meet the state construction standards; hiring it out requires a DNR-permitted contractor. No separate county well ordinance was found.

Full utility disconnection. No outright county ban on going off-grid from public water and sewer turned up. But the county's building permit process does check that you have either a septic permit from the Health Department (or approval from a sewer district) and a water availability letter, so private well plus septic is a workable path, it's just verified at permit time rather than left unchecked.