Accessory Structures in Cass County, MO (2026)
3 rules for unincorporated Cass County, Missouri.
Verified from official government sources
ADU Rules
Cass County allows a small accessory dwelling, what the Zoning Order calls a 'transitional living dwelling,' only by Special Use Permit on Agricultural, Rural Residential or Rural Suburban lots in unincorporated Cass County, capped at 900 square feet and restricted to caretaking arrangements for family members.
Cass County Transitional Dwelling ADU Rules
Significant RestrictionsCass County Code § 400.030(A)(23)
Accessory structures may not be used as a dwelling, except that on a conforming lot which is zoned as Agricultural (A), Rural Residential (R-R) or Rural-Suburban (R-S) a single, transitional living dwelling no larger than nine hundred (900) square feet may be allowed by Special Use Permit.
ADU Rental Restrictions
Cass County allows a small accessory 'transitional' dwelling for family members needing care, but the Zoning Order flatly bars charging rent for it. The unit is capped at 900 square feet, needs a Special Use Permit from the Board of Zoning Adjustment, and cannot carry its own mailing address.
Cass County Bars Rent on Transitional Living ADUs
Significant RestrictionsCass County Code § 400.050
DWELLING, TRANSITIONAL A single-family accessory dwelling, attached or adjacent to the principal dwelling on the parcel, occupied temporarily by not more than two (2) adult individuals, who, due to human frailty, are in the care and custody of the residents of the principal residence. The intent of this temporary use is to accommodate transitional living needs of family members, and not to prov...
Shed & Carport Rules
In unincorporated Cass County, a one-story detached shed, tool building or similar accessory structure under 400 square feet does not need a Building Codes Department permit, though it still must satisfy the Zoning Department's setback and zoning permit rules under Section 500.010(B)(5).
Cass County Shed Building Permit Exemption
Some RestrictionsCass County Code § 500.010(B)(5)
One-story detached accessory structures used as tool and storage sheds, playhouses and similar uses, provided the floor area does not exceed four hundred (400) square feet (37.1 m2). FPN: This exception from a building permit from the Building Codes Department does not preclude the requirement for a building permit to be obtained from the Cass County, Missouri Zoning Department or meeting the C...
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