Building permits, zoning and land rules in Marshall County, Iowa

Yes. In unincorporated Marshall County, excavating for, erecting, constructing, reconstructing, enlarging, altering or moving a building or structure requires a building permit from the Zoning Administrator¹. A structure of 120 square feet or less does not need that building permit¹. Applications require duplicate plans, site and lot information, the intended use, staking before construction and the required fee; the county reviews them for zoning, floodplain and platting compliance¹.

Marshall County publishes a value-based fee schedule: work valued from $0 through $10,000 is charged 3% of value, while work valued at $10,001 or more is charged $300 plus 0.2% of total value². We could not confirm the residential building code, inspection schedule or certificate-of-occupancy process for county permits; ask Marshall County Planning & Zoning what plans, inspections and closeout apply before ordering materials⁸.

Marshall County Planning & Zoning is the first stop for building permits and land-use questions on unincorporated property; the office assists with land-use policy and regulatory enforcement⁸. The office is in the Marshall County Courthouse at 1 E. Main St., Suite 140, Marshalltown, IA 50158, and its office phone is 641-844-2707⁸.

Permit administration is split by subject. Marshall County Environmental Health handles county septic and private-well matters, while Engineer & Secondary Roads requires a permit for a driveway or entrance coming from county right-of-way^3,9. A project in a Special Flood Hazard Area or floodplain also requires a floodplain development permit and may require state and federal permits¹⁰. The applicant for a county building permit must be the owner, contract buyer of record or an agent authorized in writing¹.

All of unincorporated Marshall County is zoned, and permits are required for most structures, including dwellings, pole buildings, decks and signs². Incorporated cities are outside the county ordinance's territory, so a parcel inside city limits needs an answer from that city rather than the county².

The county ordinance uses multiple districts with different permitted uses and dimensional schedules⁵. Lots cannot be divided below the applicable district's minimum width and area unless the Board of Adjustment permits it or the land is added to another parcel to meet the ordinance¹. Setback treatment also depends on the parcel; for example, the front-yard setback applies along both street sides of a corner lot platted after the ordinance took effect¹. Ask Planning & Zoning to confirm the parcel's district, permitted use, lot dimensions, setbacks, floodplain status and any special-use process before designing a site plan⁸.

Marshall County Environmental Health is the local authority for private sewage systems serving 4 homes or fewer or fewer than 15 people, and a county septic permit is required under county requirements and Iowa's siting, construction and permitting rules^3,11. Iowa DNR sets minimum standards and has primary responsibility for larger public systems³.

Off-grid living does not create a wastewater exception: when public sewer is unavailable, a building where people live, gather or work must have an approved private sewage system, and wastewater cannot be discharged to a ditch, waterway, the ground, groundwater, an abandoned well, an agricultural drainage well or a sinkhole¹¹. Only 4.9% of Marshall County soils are rated without severe limitations for a conventional septic drain field, so make the site evaluation an early contingency rather than assuming a standard field will fit¹². A private system serving a building must generally be inspected before a qualifying ownership transfer, and the statewide rule includes exceptions and a binding-agreement process when temporary conditions prevent inspection⁴. Contact Environmental Health at 641-844-2707 before closing or fixing a house location to confirm the permit application, soil analysis and transfer paperwork¹³.

In unincorporated Marshall County, an RV, fifth-wheel trailer or camper used as a habitation for more than 90 days in any 365-day period requires a special-use permit¹. The county materials reviewed do not establish a separate general temporary-camping rule, so ask Planning & Zoning how shorter stays, utilities and active construction affect the parcel⁸.

Marshall County has no confirmed rule written specifically for tiny homes. A small dwelling still has to fit the parcel's zoning district and applicable dwelling standards; in the R-3 example, a one-story dwelling needs at least 1,000 square feet of ground-floor area and a two-story dwelling needs at least 800 square feet, excluding open porches, garages and steps¹. Manufactured homes are allowed in the A-1 agricultural district when placed on a permanent foundation, converted to real property and taxed as a site-built dwelling¹.

1. Confirm that the parcel is outside city limits, then ask Marshall County Planning & Zoning for its district, allowed residential use, setbacks, floodplain status and platting constraints^2,8.
2. If land will be divided, resolve subdivision approval and required improvements before relying on a new lot as buildable¹.
3. Confirm legal access; if the entrance comes from county right-of-way, file the driveway permit with Engineer & Secondary Roads^9,14.
4. Apply to Environmental Health for the required septic permit and establish whether the site can support the proposed system¹¹.
5. Resolve utilities: private sewage disposal is prohibited where public sewer is available or connection is locally required; if a private well will serve a new dwelling, its permit must precede the building permit^7,11.
6. If the site is in a floodplain, obtain the floodplain development permit and any required state or federal approvals¹⁰.
7. Submit duplicate plans, site information, intended use, staking and the fee to Planning & Zoning before excavation or construction¹.

Start with jurisdiction and zoning: confirm whether the parcel is unincorporated, identify its county zoning district, and verify that the intended dwelling and accessory uses are allowed². Check recorded access as carefully as physical access because the county requires qualifying road frontage or a qualifying private easement for a residential lot¹⁴. If the tract will be split, confirm subdivision approval and improvement obligations before closing¹.

Budget for soils and wastewater before treating a site as buildable; only 4.9% of county soils rate without severe limitations for a conventional drain field¹². An off-grid plan still needs an approved private sewage system when public sewer is unavailable¹¹. Check public-water availability because private sewage disposal is prohibited where public sewer is available or a local ordinance requires connection, and a private well permit will not be issued where community or public water is available^7,11. A floodplain site requires a county development permit and may need state and federal permits¹⁰. For cost context, the effective property-tax rate is 1.5% and the median annual bill is $2,030¹².