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 to 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
Des Moines ADU permit questions
- Do I need a permit to build an ADU in Des Moines?
- Yes. An accessory dwelling unit (ADU) in Des Moines requires a building permit. ArchPermit tracks 14 cited requirements for this jurisdiction (11 required, the rest conditional). Always confirm the exact forms, fees, and code edition with the local permitting authority that issues the permit.
- What does an ADU permit package require in Des Moines?
- Core required items include: Building Elevations; Building Permit Application + General Information; Cross Sections; Description of Work (Scope); Details + Door/Hardware/Room-Finish Schedules; Electrical / Mechanical / Plumbing Plans (separate permits), plus 5 more. Each requirement links to its authoritative source, and nothing is permit-ready until an independent licensed professional reviews and seals it.
- How are ADU permits submitted in Des Moines?
- Des Moines accepts permit submittals via Customer Self-Service (CSS) portal (EnerGov). ArchPermit prepares a draft package you can submit there after a licensed architect reviews and seals it.