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ADU rules by city

ADU rules for every Des Moines-metro city.

Iowa's 2025 law lets you build an ADU anywhere in the metro — but each city handles the details a little differently. Start with the statewide rules, then find your town.

The rules that apply everywhere

Iowa's statewide ADU baseline.

Because Iowa's 2025 law (SF 592) is a state mandate, these protections apply in every metro city — no matter what a local code still says:

One ADU by right
At least one ADU allowed on a single-family lot, approved without a discretionary hearing.
Size: 1,000 sq ft or half your home
Whichever is larger. A 2026 update (SF 2629) measures this as gross living area — garages, decks, and unheated porches don't count, and unfinished basements don't count toward the cap.
No owner-occupancy rule
You don't have to live on-site — investors can build and rent by right.
No stricter rules than the main house
Cities can't impose tougher setbacks, height, design-matching, or extra parking than they apply to your primary home.

Want the full statewide picture, including size math, permitting, and returns? Read the complete Iowa ADU guide.

What changes city to city

The state sets the floor; each city fills in the rest. Local differences worth checking include what the town calls an ADU, its permit office and fees, review timelines, historic-district review, PUD and HOA rules in newer subdivisions, and septic or well limits on unincorporated fringes. That's what each city guide below covers.

Find your city

Des Moines

Polk

The metro anchor — Chapter 134, no impact fees, 10-year tax abatement.

View rules →

West Des Moines

Polk · Dallas

State baseline applies while the city code catches up — watch for PUD and HOA rules.

View rules →

Urbandale

Polk · Dallas

A clear ADU ordinance: two-bedroom cap, 30% rear-yard limit, reduced setbacks.

View rules →

Ankeny

Polk

One of the metro's fastest-growing suburbs.

Guide coming soon

Waukee

Dallas

Rapid growth on the metro's west edge.

Guide coming soon

Altoona

Polk

East-metro growth near Prairie Meadows.

Guide coming soon

Clive

Polk · Dallas

Established west-metro neighborhoods.

Guide coming soon

Bondurant

Polk

Fast-growing northeast suburb.

Guide coming soon

Carlisle

Warren · Polk

South-metro; spans county lines — confirm which applies.

Guide coming soon

Norwalk

Warren

Growing south-metro community.

Guide coming soon

Don't see your town, or on an unincorporated parcel? The state law still applies — tell us your address and we'll confirm the rules for your specific lot.

Confirm the rules for your exact lot.

Tell us your address and we'll check what your city and parcel allow, then put the cost and return in writing. Free, no obligation.

City rules are being updated to match Iowa's 2025 and 2026 ADU laws and vary by parcel. This page is general information, not legal advice; confirm specifics with your city's planning or zoning office before you build.