Story County, IA Building Setbacks & Zoning: Lot Coverage Limits (2026)
Key Facts
- Maximum lot coverage
- 50 percent of lot area (RMH District)
- Governing section
- Story County Code Sec. 86.09(6)(A)
- Minimum development size
- 5 acres
- Road right-of-way setback
- 30 feet minimum
- First-offense civil penalty
- up to $750.00
- Repeat-offense civil penalty
- up to $1,000.00
Summary
In unincorporated Story County, the RMH Residential Manufactured Housing District caps building lot coverage at 50 percent of the lot area under Story County Code of Ordinances Section 86.09(6)(A). No manufactured home, accessory building or common facility may push the district past that ceiling. The Planning and Development Department enforces the limit through the zoning permit required for every development in the district.
6. Bulk Requirements. A. The maximum lot area to be covered by all structures shall not exceed 50 percent.
Full Breakdown
09(6)(A), which governs the RMH Residential Manufactured Housing District, the county's zone for planned manufactured housing communities. 09(5)(B)(1). Within that five-acre minimum, the 50 percent figure caps the ground footprint of every manufactured home, accessory structure (garages, carports, storage buildings) and common facility building combined; Table 86-7 then layers individual front, rear and separation setbacks on top, so a development can sit under 50 percent coverage and still fail on setback distance. 11, and conditional uses inside the district (see Chapter 90) must additionally meet the external separation standards and Table 86-7 yard requirements unless the Board of Adjustment specifies otherwise.
Because the cap sits in the RMH district provisions specifically, it does not apply to the county's other residential districts (A-R, R-1, R-2), which regulate bulk through setbacks and height rather than a stated coverage percentage; a manufactured home placed as an accessory dwelling unit on an ordinary residential lot instead follows the bulk requirements for single-family dwellings in that district, not this 50 percent figure.
Violations & Fines
Story County enforces Land Development Regulation violations under Sections 93.02 and 93.03. Planning and Development staff first seeks voluntary compliance, giving 30 days to correct or submit a compliance schedule. Uncorrected violations can bring a citation and a civil penalty of up to $750.00 for a first offense and up to $1,000.00 for each repeat offense (Code of Iowa Sec. 331.307[1]), or prosecution as a simple misdemeanor; each day of continued violation counts as a separate offense, and a Notice of Violation may be appealed to the Board of Adjustment within 30 days.
Frequently Asked Questions
Does the 50 percent lot coverage cap apply to every home in unincorporated Story County?
What counts toward the 50 percent figure?
Who reviews a manufactured housing development for compliance?
What happens if a development exceeds the coverage limit?
Sources & Official References
Other rules in Story County
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