Off-Grid Living in Cass County, Missouri

If you're eyeing raw land in Cass County, Missouri for an off-grid setup, here's what I found in my research. The big thing to understand upfront: Cass County is one of the relatively few rural Missouri counties that actually adopted countywide zoning for its unincorporated areas, through a Zoning Order administered by the County Planning Board and Zoning Department. But that only covers unincorporated land. If you're inside Harrisonville, Belton, Raymore, Pleasant Hill or another city, that city runs its own separate zoning and building department, and the rules I describe here won't apply directly, you'd need to check with the city.

On zoning, land classified Agricultural needs to be at least 20 full acres to keep commercial farming/ag use; smaller parcels don't qualify for that designation, per the county's Zoning Order.

For dwellings, the county sets a minimum size, per its 2007 Amended Zoning Order: new homes, including manufactured homes, need to be at least 1,000 square feet. Manufactured homes must also be 1976 or newer and carry a federal HUD seal. Accessory structures, which would include small cabins, sheds, or a "tiny house" setup, cannot legally be used as a standalone dwelling under county rules. I did not find county-specific language on RV residency, so I'd treat that as unclear and confirm directly with the Zoning Department.

Building-wise, Cass County adopted the International Residential Code (2006 edition, as amended) and International Building Code for the unincorporated county. Small accessory buildings under 400 square feet used as sheds or similar are exempt from a building permit, though zoning approval may still apply. There's also a separate size/height limit on certain pole-barn-style ag buildings.

Septic is a big one here: Cass County's Environmental Health Department runs its own detailed onsite wastewater ordinance, separate from just following state rules. You need a permit, a soil evaluation, and a state-registered installer. Minimum lot size for a conventional septic system is 3 acres; evaporation pond systems need 5+ acres. I found no standalone composting-toilet exemption, so any bathroom, even in an accessory building, appears to need to tie into an approved wastewater system, per the ordinance.

Greywater has no clear standalone rule I could find; the county's wastewater ordinance seems to fold greywater into the broader "sewage" definition, so I'd call this genuinely unclear and worth a direct call to Environmental Health.

Rainwater harvesting looks fine, I found nothing banning it at the county level, just general stormwater/erosion rules, so it falls back on the generally permissive state baseline.

Wells are governed mainly by Missouri DNR's statewide well rules; I didn't find a separate county well ordinance, though subdivisions using private wells and septic need DNR/DHSS sign-off.

Bottom line: off-grid living looks workable in unincorporated Cass County if you meet the dwelling size, building code, and septic requirements, but always double-check with the county directly since local rules can shift.