Basement Finishing Permits and Code Across the Des Moines Metro

There is no such thing as a Des Moines metro building code. There are a dozen of them, and on the day you decide to finish a basement, the only one that matters is the one adopted by the city whose name is on your water bill. A house in Des Moines proper is judged against the 2024 International Residential Code, adopted effective January 1, 2026. A house eight miles west in West Des Moines is judged against the 2015 edition. A house in Indianola is on the 2018. Those are not trivial differences, and a bid drawn to the wrong book gets caught at the framing inspection, not at the counter.

This is a plain walk through what actually governs a basement finish in the metro: which code edition applies where, what the egress window has to measure, what the permit costs, when an inspector has to see the work before it gets covered, and what changed in Iowa law in 2026. Every figure below comes from a published city document, a county checklist, the Iowa Administrative Code, or the Iowa Code itself. Where a city has not published a number, this page says so rather than guessing, because a guessed fee is worse than no fee at all.

Which code edition is my basement judged against?

The City of Des Moines states that effective January 1, 2026, the 2024 International Building Code, 2024 International Residential Code, 2024 International Existing Building Code and 2024 International Fire Code are adopted. Alongside those it lists the State Mechanical Code adopting the 2024 IMC, the 2021 edition of NFPA 54, the State Electrical Code adopting the 2023 NEC, the State Plumbing Code adopting the 2024 UPC, the 2015 IECC, and SUDAS for public improvements. That is a modern stack, and it is the one most metro contractors quote from because Des Moines is the biggest single market.

Step outside the city line and the picture changes. West Des Moines publishes its adopted codes as the 2015 IBC, 2015 IRC, 2015 IPMC and 2015 IFC with local amendments, the 2017 NEC, the 2012 IECC, the 2018 IMC and the 2018 UPC. Indianola adopts the 2018 IRC including Appendix Chapters M at code section 151.01 and the 2018 IBC at section 156.01. And the state's own code, at Iowa Administrative Code rule 481-301.8, adopts the 2024 IRC - which reaches into any city over fifteen thousand people that has not adopted a substantially conforming local code, under Iowa Code section 103A.10(2)(d).

• Des Moines: 2024 IBC, IRC, IEBC and IFC, effective January 1, 2026
• West Des Moines: 2015 IBC, IRC, IPMC and IFC with local amendments; 2017 NEC; 2018 IMC; 2018 UPC
• Indianola: 2018 IRC including Appendix Chapters M (section 151.01); 2018 IBC (section 156.01)
• State building code (IAC 481-301.8): 2024 IRC, reaching cities over 15,000 without a conforming local code

How big does a basement bedroom window have to be?

If the finished basement includes a sleeping room, it needs an emergency escape and rescue opening, and the dimensions are not negotiable. Polk County's finished basement and interior remodel permit checklist lists them in a single block: net clear openable area of not less than 5.7 square feet, which the checklist spells out as 820 square inches; opening height not less than 24 inches; opening width not less than 20 inches; sill height not more than 44 inches above the floor; and a window well measuring at least 36 inches horizontally from the foundation wall to the well.

The state code says the same thing in more careful language. Iowa Administrative Code rule 481-301.8 adopts the 2024 IRC, whose section R319.1 puts the sill no more than 44 inches above an adjacent permanent interior standing surface that is itself no less than 36 inches wide and 18 inches deep and no more than 24 inches high - which is how a permanent step below the window becomes a legitimate way to make a high sill work. Window wells are covered at R319.2. There is an exception for basements not more than 200 square feet used only to house mechanical equipment, but a 200-square-foot rec room is not it.

Alarms travel with the bedroom. West Des Moines's own building handout requires smoke alarms meeting NFPA 72 and listed to UL 217, dual sensor, installed in each sleeping room, outside each separate sleeping area in the immediate vicinity of the bedrooms, and on each story of the dwelling including basements. Carbon monoxide alarms are required to be listed to UL 2034. These are cheap items that fail inspections constantly, usually because someone put the basement alarm in the rec room and not in the new bedroom itself.

• Net clear opening: not less than 5.7 square feet (820 square inches)
• Opening height: not less than 24 inches; opening width: not less than 20 inches
• Sill height: not more than 44 inches above the floor or adjacent permanent standing surface
• Window well: at least 36 inches measured horizontally from the foundation wall
• Smoke alarms in the new bedroom, outside the sleeping area, and on the basement story

What will the permit actually cost?

Des Moines publishes a flat-rate schedule. Its Permit and Development Center fee sheet, headed as new fees effective 1-1-26, lists renovations to dwellings at $154.50 and additions to dwellings at $257.50. The electrical, plumbing and mechanical permits for alterations and additions to existing dwellings are $77.25 each. A basement finish that moves a drain, adds circuits and reworks a supply run therefore carries the $154.50 building permit plus up to three $77.25 trade permits. If the permit expires, reinstating it for an additional year costs $25.75.

Adel does it the older way, by valuation. The city's published schedule starts at $22.00 for work valued between $1 and $500 and steps up as the declared value rises, with re-inspections billed at $42.00 per hour on a one-hour minimum. West Des Moines publishes a valuation figure rather than a fee for this work: finished basement area is valued at $85.00 per square foot for permit purposes, which is the number a plan reviewer will use to compute the fee whether or not it resembles what you are actually paying a contractor.

Several metro cities do not publish a basement-specific fee at all, and this page will not invent one for them. Bondurant, for instance, publishes its application process clearly but not a fee table on the same page. The right move is to call the building department, state the declared valuation, and get the number before you sign anything - and then ask separately whether trade permits are billed on top, because in Des Moines they are.

• Des Moines: $154.50 renovations to dwellings; $257.50 additions; $77.25 each for electrical, plumbing and mechanical
• Des Moines: $25.75 to reinstate an expired residential permit for an additional year
• Adel: valuation-based, starting at $22.00 for work valued $1-$500; re-inspection $42.00 per hour, one-hour minimum
• West Des Moines: finished basement valued at $85.00 per square foot for permit purposes

When does an inspector need to see the work?

Before it is covered - that is the whole rule, stated four different ways across the metro. Polk County's finished basement checklist puts it bluntly: all work must be inspected and approved by Polk County prior to concealing any installation. West Des Moines's handout lists footings prior to concrete being placed, and framing and electrical rough-in if the work is to be enclosed or covered before the final inspection. Indianola lists a Foundation Inspection, Framing Inspection, Footings and Setbacks Inspection, a Tar, Tile and Gravel Inspection, and a Final Building and Zoning Inspection.

On a basement finish specifically, the sequence collapses to one critical call: the rough-in inspection after framing, wiring, plumbing and any mechanical changes are complete, and before insulation and drywall. Everything you might want to argue about later - joist penetrations, fire blocking, a beam pocket somebody notched - is visible on that day and invisible after it. Drywalling ahead of the call is the most expensive mistake available on this job, because the remedy is to open the wall back up at your cost.

Permits also have a clock. Polk County's checklist states that work must commence within 180 days from the permit issuance date and be completed and inspected within one year. Des Moines charges $25.75 to reinstate a residential permit for an additional year after it has expired. Neither is a large penalty, but both are avoidable, and an expired permit on a house that later goes on the market is an awkward thing to explain to a buyer's agent.

What changed in Iowa in 2026, and does it apply to my house?

House File 2297 added a new section 103A.8E to the Iowa Code requiring that new single-family or two-family residential construction include a passive method for the mitigation of radon listed in appendix AF of the International Residential Code, 2021 edition, published by the International Code Council. It also amended section 103A.10 so that provisions of the state building code relating to radon mitigation apply to all new single-family and two-family residential construction in the state - which means no city can opt out of it.

The bill moved fast and nearly unopposed. It was introduced on February 5, 2026, passed the House 87 to 4 on March 12, passed the Senate 46 to 0 on April 29, was repassed by the House 81 to 3 on April 30 after concurrence in a Senate amendment, and was signed by the governor on May 19, 2026. It appears in the session laws as Acts chapter 1124.

Here is the part homeowners keep missing: the statute says the requirement applies only to single-family or two-family residential construction commenced after the adoption of the requirement. It is a new-construction rule. It does nothing for the house you already own, and it does not require anyone to mitigate an existing basement before finishing it. Given that the Iowa Radon Survey found 71.6 percent of Iowa homes above the EPA's 4 pCi/L action level, the sensible order of operations on an existing house is to test first, decide about mitigation second, and frame third.