Des Moines ADU permit requirements
Last reviewed: June 22, 2026
Quick answer
Permitting an accessory dwelling unit (ADU) in Des Moines, Iowa means pulling a building permit from the local authority that issues it. ArchPermit tracks 14 source-cited requirements (11 required, the rest conditional) for this jurisdiction. Submittals go through Customer Self-Service (CSS) portal — EnerGov. These requirements were last reviewed June 22, 2026; confirm the exact forms and fees with the local permitting authority.
A source-cited checklist of what an ADU (accessory dwelling unit) permit package needs in City of Des Moines. Every item links to its authoritative source; items that vary are flagged to confirm locally.
(Des Moines, Iowa — not Des Moines, WA.) Des Moines calls them 'Accessory Household Units' (AHUs), governed by Zoning Ordinance Chapter 134 § 3.9.2. By-right in the A, DXR, RX1, and RX2 districts; in N/NX districts allowing 2–4 household units per lot; and in N/NX regardless of unit count if the lot is within 0.25 mi of a public transit route. A Board of Adjustment conditional-use approval is required for an AHU in an N district that allows only one household unit per lot. One AHU per lot; max 50% of the principal unit's floor area (or 1,000 sf, whichever larger); detached AHUs go in a detached outbuilding; no additional parking required. Owner-occupancy is in conflict — the 2019 Chapter 134 PDF requires it but the current live ADU page omits it (a May 2022 amendment eased AHU rules); confirm against the live code.
- Building Elevationsrequired
Exterior elevations of all sides; finish materials/type/color; wall and opening areas.
source · reviewed 2026-06-22 - Building Permit Application + General Informationrequired
Project name, address, and detailed description of work, applied via the CSS portal.
source · reviewed 2026-06-22 - Cross Sectionsrequired
Footing-to-roof section; floor/roof/eave heights; roof pitch; wall covering; insulation type & amount.
source · reviewed 2026-06-22 - Description of Work (Scope)required
Identifies the scope and extent of the work.
source · reviewed 2026-06-22 - Details + Door/Hardware/Room-Finish Schedulesrequired
How elements are constructed (wall types, stair geometry, handrails/guardrails); door types/sizes/ratings; wall/ceiling/floor finishes and ceiling heights.
source · reviewed 2026-06-22 - Electrical / Mechanical / Plumbing Plans (separate permits)required
Each trade requires a separate permit and plans (lights/panels/receptacles; HVAC + ventilation calcs; fixtures + supply/waste/vent).
source · reviewed 2026-06-22 - Energy Review / Code Compliance (signed & sealed)required
Demonstrates conformance with the City's adopted Energy Code (prescriptive path).
source · reviewed 2026-06-22 - Foundation / Footing Planrequired
Location, size, type of footings & foundation; reinforcing size/type/spacing; soil bearing; section views.
source · reviewed 2026-06-22 - New / Proposed Floor Plansrequired
Proposed layout & uses, fully dimensioned; room labels; door/window locations & sizes; smoke-detector, plumbing-fixture, and mechanical-equipment locations.
source · reviewed 2026-06-22 - Roof Planrequired
Roof slope, drain locations, and covering type/material/fire classification.
source · reviewed 2026-06-22 - Site Planrequired
North arrow, property lines, lot dimensions/area, structure size & distances to property lines, impervious surfaces, driveway width, trees on lot & in ROW, utility-connection locations, sidewalk, and easements (per Code Ch. 134 & 135).
source · reviewed 2026-06-22 - Board of Adjustment (Conditional-Use) Decision & Orderconditionalverify locally
Required only where the AHU is conditional (e.g. an N district allowing one unit per lot) — attach the BOA approval.
source · reviewed 2026-06-22 - Professional Certifications (Iowa-licensed design professional)conditional
Plans certified by an Iowa-licensed architect/engineer where required.
source · reviewed 2026-06-22 - Structural Plans + Certified Calculationsconditional
'May be required' — calcs signed & sealed by an Iowa-licensed engineer for non-conventional framing.
source · reviewed 2026-06-22