Greene County, MO Accessory Structures: ADU Rules (2026)

Greene County exercises zoning authority over its unincorporated territory through the Greene County Zoning Regulations, first adopted by the County Commission on December 26, 1978 with subsequent amendments. The Planning and Zoning Office (within Resource Management) issues zoning determinations and conditional use permits. Article V governs the A-1 Agriculture District, which historically allows a wider range of accessory uses than the R-1 single-family residential district. Whether a detached accessory dwelling is permitted, permitted as a conditional use, or prohibited depends on the specific zoning district of the parcel; applicants should confirm with the Planning and Zoning Office before designing or starting construction. Building permits and code review (under the 2012 International Codes and 2011 National Electric Code adopted by the County, with amendments) are issued by the Building Regulations Office (417-868-4015). On-site wastewater capacity is reviewed under the Greene County Wastewater Standards when public sewer is not available, which often becomes the practical limit on adding a second dwelling. Missouri has not enacted a statewide ADU preemption statute, so the operative rules are the county zoning code (unincorporated) or the relevant city's code. Inside the City of Springfield, Springfield's Land Development Code governs; check Title 36 of the Springfield Code for ADU and accessory structure provisions.