Mahaska County, Iowa Building Permit Guide

On unincorporated land, Mahaska County does not issue building permits: the building-permit sections that Ordinance 32 carried in the 2020 code are gone from the 2026 code, and on May 4, 2026 the Board of Supervisors approved the update to all ordinances “with the removal of Ordinance 37”, the code book’s ordinance for rural building permits. What a rural build still needs comes from the County Engineer (entrance, address, floodplain, utility permits) and the County Sanitarian (septic and well permits), both on 641-672-2897, plus a state electrical permit.

What requires a permit in rural Mahaska County?

Mahaska County has no building code, no zoning ordinance and, since the 2026 recodification, no building permit for unincorporated land. Earlier codes did: the 2020 code’s Ordinance 32 required owners to apply to the County Engineer for a $350 building permit with a drawing of the building, driveway, water and sewer. The 2026 code keeps Ordinance 32 only as a rural subdivision ordinance, and the board removed a separate Ordinance 37 on rural building permits before adopting the update. That leaves a set of narrower county permits.

The state still regulates parts of every project: electrical work needs a state permit and inspection, and the state energy, plumbing and mechanical requirements apply whether or not a county adopts a code.

What the county decides and what the state holds

The county’s choices are in its Code of Ordinances (2026 edition): Ordinance 31 (onsite wastewater), Ordinance 32 (subdivisions), Ordinance 33 (floodplain management), Ordinance 36 (private wells, adopting the state well rules in chapters 38 and 49 of the environmental protection rules), Ordinance 23 (utility permits) and Ordinance 54 (commercial wind). The minutes of August 7, 2025 record that the county once had a board for zoning and building permits that was later dissolved, and the Sanitarian has raised with the board how the lack of planning and zoning affects the county.

Mahaska County building department: who handles permitting

Two county offices share the Secondary Roads Office building at 2074 Old Highway 163. The County Engineer handles entrances, addresses, utility and right-of-way permits, floodplain development applications and subdivision plats. Environmental Services, led by Sanitarian Eric Dursky, issues septic and well permits, licenses septic contractors and reviews water and wastewater plans.

Around Oskaloosa the city adds a layer: since September 19, 2023 its zoning reaches two miles beyond the city limits, so non-agricultural development in that ring needs Oskaloosa zoning review and approval, although construction building permits and inspections are not required there at this time. Subdivisions within two miles of a city that supervises that area are reviewed by the city’s Planning and Zoning Commission as well as the Board of Supervisors.

Cities in Mahaska County

Each incorporated city handles building permits, if it issues them, inside its own limits; the county permits above apply on rural land, and a new address inside a city comes from the city.

Mahaska County permit types

Most county permits are paper forms posted on the Engineer’s forms page; septic permits and septic contractor licenses are handled through the county’s GeoPermits portal, and the Engineer’s page also links a “One Stop Permit” application in the same system.

Residential permits

For a new rural house the sequence is driveway, address, septic and, for a private water supply, well. The entrance permit costs $25, is non-refundable and expires six months after issue; the driveway top must be 24 to 48 feet wide, the location flagged or staked, and a certificate of liability insurance naming Mahaska County as an additional insured enclosed, and the entrance must follow the county’s access policy. The address application then needs the driveway approved and staked; Secondary Roads records the location, the 911 Center assigns the number and the county shop installs the house number marker.

Building or remodeling a home here? Alliance handles residential permit applications, so the crew isn't waiting on the counter.

Commercial permits

Businesses use the same entrance and address process; an address for anything other than a residence or primary business location carries a $50 addressing fee payable to MCEMA, due before the request is processed. Commercial wind energy systems are the one use with a county building permit: Ordinance 54 requires a special use permit approved by Board resolution and then a commercial wind energy conversion system building permit from the county’s Economic Development Director, based on a final development plan, before construction. Utility lines along county roads need a utility permit under Ordinance 23, and other work in the right of way needs the Engineer’s approval for construction on county right of way.

For tenant improvements and new commercial builds, Alliance handles commercial building permits through issuance. More on this: commercial building permits explained.

What comes before construction

• Floodplain. Any development in a flood hazard area, including filling, grading and placing a factory-built home, needs a floodplain development permit first. The lowest floor of a new or substantially improved house, basement included, must be at least 1 foot above the 100-year flood level, and the Sanitarian must approve the sanitary system before this permit is issued. Non-residential buildings may instead be floodproofed to the same level, certified by a professional engineer registered in Iowa, and the application asks for the base flood elevation, the 1993 flood elevation and the proposed lowest floor.
• Subdivision. Dividing land into three or more lots needs a surveyed plat; the preliminary plat goes to the County Engineer and is reviewed by the Engineer, the Sanitarian and the Board of Supervisors.
• City zoning ring. Within two miles of Oskaloosa, non-agricultural uses need the city’s zoning approval.

Mahaska County permit costs and fees

With no county building permit, the costs of a rural build are the specific permits below. Septic fees are set in Ordinance 31 of the 2026 code and plat fees in Ordinance 32; the entrance and address fees are printed on the Engineer’s forms.

A typical new rural house therefore pays $25 for the entrance and $250 for a conventional septic system to the county, with no county building permit fee, and buys its electrical permit from the state. Under the 2020 code the same house would also have paid a $350 building permit to the County Engineer; anyone working from older county paperwork should know that fee no longer appears in the code. Septic permits are valid for 12 months, and once a soil analysis has been done the septic permit fee is not refunded.

Trade permits and who may pull them

• Electrical: the county runs no electrical inspection program, so permits for rural work are bought from the state through iowaelectrical.gov, and a state electrical inspector has three business days from receiving an inspection request to carry out the inspection.
• Septic: anyone who builds, alters or repairs a private sewage system in the county must hold the county’s septic contractor license ($150 a year), and renewals need 12 hours of classroom instruction.
• Wells: private wells need a county well construction permit under Ordinance 36 and are built to the state well rules.
• Plumbing and mechanical: no county permits; the work follows the state codes and is done under state licenses.

Contractors earning $2,000 or more a year register with DIAL. The septic license is the only contractor license in the county’s ordinances, and Environmental Services posts a homeowner septic system checklist on its page alongside the permit portal.

How to get a new rural building permitted in Mahaska County

Review, corrections and what causes delay

Septic installations wait on the Sanitarian’s site evaluation, and a septic system may not be put into use until its construction has been inspected and approved. In a floodplain, the permit waits on documented sanitary approval and on elevation data. The rules may change: the June 12, 2026 agenda listed “Consider rewriting Ordinance 37 that was not adopted requiring building permit”, and the minutes record only the Board’s consensus to have a work session to discuss it. No later action appears in the minutes posted through August 3, 2026 or the agendas posted through November 2, 2026. The subject first came up when the Assessor raised building permits at the Board’s August 7, 2025 meeting, where concerns were brought up about lost county revenue when property updates and new buildings are not disclosed to the assessor; during the April 2026 public hearings on the recodification, residents commented on the ordinance language and on permit fees for small buildings.

Inspections in Mahaska County

The county makes no building inspections. The Sanitarian inspects septic systems, which may not be covered before the final inspection, and each extra or repeat inspection costs $150. The County Engineer’s staff review each entrance application in the field, and the review report records items such as the depth of cover, with 12 inches the minimum. For electrical work, request the state inspection through iowaelectrical.gov after buying the permit.

Septic systems are also inspected when a property is sold: the time-of-sale inspection costs $300.

Iowa building code

Mahaska County has adopted no building code for unincorporated land and issues no general building permit there. FEMA’s Community Status Book lists Mahaska County (community 190888) as participating in the National Flood Insurance Program, with a current effective map dated June 16, 2011, which FEMA marks as a map with no elevations.

Iowa lets most cities and counties adopt the state building code, another code or none (a city of more than 15,000 must enforce at least the state code), but the energy, accessibility, fire, plumbing, mechanical and electrical rules apply statewide. Iowa rules

Mahaska County permit search and official resources

Septic, well, entrance, address and floodplain records are kept by the Sanitarian and the County Engineer and can be requested as public records under Iowa Code chapter 22. Board of Supervisors agendas and minutes, including any action on rural building permits, are posted on the county’s minutes page. The 2020 code book is still posted beside the 2026 one; its Ordinance 32 building-permit pages describe the old Engineer procedure and $350 fee, not the current rules.

• Mahaska County ordinances
• Code of Ordinances, 2026
• Code of Ordinances, 2020 (superseded)
• Board of Supervisors agendas and minutes
• Minutes, May 4, 2026 (update approved with the removal of Ordinance 37)
• Minutes, June 12, 2026 (Ordinance 37 work session)
• County Engineer
• Engineer forms
• Entrance permit application
• New address application
• Floodplain development application
• Environmental Services (Sanitarian)
• Septic permits and contractor licensing portal
• Homeowner septic system checklist
• City of Oskaloosa two-mile zoning notice
• Iowa electrical permits (iowaelectrical.gov)
• FEMA Community Status Book, Iowa

Mahaska County building permit FAQs

Do I need a building permit to build a house in rural Mahaska County?

Not from the county in 2026. You still need an entrance permit, an address, septic and well permits, a floodplain permit if the site is mapped, and a state electrical permit.

Didn’t the county used to charge $350 for a building permit?

Yes, under Ordinance 32 in the 2020 code. That procedure is not in the 2026 code. On May 4, 2026 the Board approved the ordinance update “with the removal of Ordinance 37” (rural building permits); on June 12, 2026 it agreed to hold a work session on rewriting it, and no later action has been posted.

How much is a septic permit in Mahaska County?

$250 for a septic tank and absorption field or a sand filter system, $150 for a holding tank, and $150 for each additional inspection.

Who issues electrical permits in rural Mahaska County?

The state, through DIAL’s iowaelectrical.gov system; the county has no electrical program.

Does Oskaloosa control building near the city?

Within two miles, Oskaloosa reviews zoning for non-agricultural development but construction building permits and inspections are not required there at this time.

How high must a house be built in a Mahaska County floodplain?

The lowest floor, including any basement, must be at least 1 foot above the 100-year flood level, under a floodplain development permit.

How do I get a rural address?

Get the driveway approved and staked, then file the new address application with Secondary Roads; the county installs the number marker.

Simplify Mahaska County permitting with Alliance Permitting

Alliance Permitting is a permit documentation and submission company in Iowa. We prepare your paperwork, file it correctly and coordinate with the permitting authority through issuance. We are not a contractor and we do not perform licensed plan review or inspections; that work stays with your licensed team and the jurisdiction.

This guide is provided by Alliance Permitting for general information about Mahaska County permitting. Requirements, fees, and procedures change; confirm details with the permitting authority before relying on them.