Polk County, IA Building Setbacks & Zoning: Lot Coverage Limits (2026)
Key Facts
- Governing table
- Zoning Ordinance Table 6.1
- Estate/Ag Transition cap
- 5% building coverage
- Rural Residential cap
- 8% building coverage
- Low Density Residential cap
- 15% building coverage
- Medium Density cap
- 30% building coverage
- High Density/Mixed Use cap
- 40% building coverage
- Enforcer
- Zoning Administrator, Public Works
Summary
Unincorporated Polk County caps how much of a residential lot can be covered by buildings using Table 6.1 of the Zoning Ordinance, with limits set per zoning district from 5% in Estate Residential up to 40% in the High Density and Mixed Use districts, and the cap applies to accessory buildings too.
Table 6.1 Table of Single-Family Bulk Standards (Standard & Cluster & Mobile Home)
Standard Single Family Regulations
Setbacks Maximum Maximum Building Building Zoning District AG Lot size Lot Front Side Rear Height Coverage
Agricultural AT 35 ac Width 50 25 50 Agricultural Transition ER 35 ac 50 25 50 40 5% Estate Residential RR 3 ac 600 75 25 75 40 5% Rural Residential LDR 600 50 15 50 35 8% Low Density Residential MDR 40000 sf 225 35 10 35 35 15% Medium Density HDR 12000 sf 140 30 8 30 35 30% High Density 75 30 8 30 35 40% 8500 sf 60 35 40% 8500 sf 60 40%
Full Breakdown
Table 6.1, the Table of Single-Family Bulk Standards, sets a Maximum Building Coverage percentage for each residential zoning district in unincorporated Polk County. Agricultural Transition (AT) and Estate Residential (RR) are capped at 5%, Rural Residential (LDR) at 8%, Low Density Residential (MDR) at 15%, Medium Density (HDR) at 30%, and High Density and Mixed Use (MU) parcels at 40%. Building coverage is defined in Article 2 as "that portion of a lot covered by any and all buildings including accessory buildings," so garages, sheds and other detached structures count against the same limit as the house.
Article 4, Division 6, Section 1(E) reinforces this for accessory structures specifically: "The building coverage area of all principal and accessory buildings and structures shall not exceed the building coverage limits for the zoning district in which located." Separate coverage tables apply to Cluster Development Option lots (15% to 40% depending on district) and to Planned Development unit types such as the bi-attached house (.44, i.e. 44%) and townhouse (.67, i.e. 67%) under Tables 6.2 and 6.3. Legal Lots of Record established before the September 10, 2007 Zoning Ordinance keep their setback allowances under Article 21, Division 1, but building coverage is not grandfathered separately from the district's Table 6.1 percentage. Any change to an approved site plan or building coverage figure runs through the Zoning Administrator in Public Works - Planning and Development.
Violations & Fines
Exceeding the Table 6.1 coverage cap is a zoning violation under Article 23. The Zoning Administrator issues a written Notice of Violation stating the problem and a correction deadline; if that does not resolve it, a Citation follows giving the owner up to 30 days to correct the violation, and each day the violation continues is charged as a separate violation. If work continues in violation after notice, the Administrator issues an immediate stop-work order posted on the property, and a violation on one parcel blocks new permits on that parcel or any other property the violator owns or operates until the violation is remedied. The Zoning Administrator may assess the maximum civil penalty per day allowed under the Polk County Code of Ordinances, and unresolved violations can be referred for civil or criminal remedies or abated by the County with costs placed as a lien on the property.
Frequently Asked Questions
Does an outbuilding count toward my lot coverage limit?
What is the lot coverage limit in Rural Residential in unincorporated Polk County?
What happens if I build over my district's coverage cap?
Sources & Official References
Other rules in Polk County
Compare Polk County to another location·View the Iowa building setbacks & zoning overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.