Des Moines ADU Permit Process
The full Des Moines, WA ADU permit pipeline from pre-application through certificate of occupancy. 0 phases, current fees, review department contacts.
Last updated 2026-05-15
We're verifying Des Moines's permit pipeline this quarter. Contact us for the current process applied to your specific project.
Des Moines permit resources
Frequently asked
What is the current Des Moines, WA ADU permit timeline?
Median Des Moines ADU permit issuance from clean submittal is 8–16 weeks in 2026. That breaks down as: intake + completeness check (5–10 business days), first review cycle (4–7 weeks across building, planning, side-sewer, addressing, drainage as applicable), corrections back to us (1–2 weeks), second review (2–4 weeks), then issuance. Pre-application meetings shave one full cycle on average. The fastest Des Moines ADU we have closed in 2025 was 6.5 weeks on a catalog plan with a pre-app; the slowest was 22 weeks because of a side-sewer easement title issue — not a planning issue.
What reviews are required for an ADU in Des Moines?
Standard Des Moines ADU review touches building, planning (zoning, lot coverage, setbacks), addressing, side-sewer (or septic where applicable), water availability, drainage review (if impervious exceeds threshold), and energy review (IECC R406 worksheet). Critical-areas review triggers if your lot is mapped for steep slope, wetland, riparian, or landslide hazard. SEPA review is rare for a single ADU but possible if other land-use actions are pending on the same parcel. Each review runs in parallel, not sequentially, which is why pre-app meetings matter.
What gets Des Moines ADU permits rejected on first review?
Top six Des Moines reviewer redlines we see: (1) IECC R406 envelope worksheet missing or calculations not matching plan assemblies; (2) side-sewer not shown on site plan with slope and invert; (3) lot coverage math omits roof overhangs (count to drip line in Des Moines); (4) Fire separation between primary and ADU walls insufficient when separation < 5 ft; (5) glazing U-factor or SHGC on schedule doesn't match window NFRC labels; (6) drainage report missing when impervious increase is over the threshold. We catch all six in our QA before submittal.
Can I expedite the Des Moines ADU permit?
Des Moines does not offer formal paid expedite for residential ADUs, but the practical accelerators are: catalog plans (reviewers see familiar details and move fast), complete drainage report at submittal, pre-app meeting on file, and using a contractor whose past submittals were clean. We track our own correction count per submittal; clean sets average 1.2 review cycles in Des Moines versus the city-wide 1.8 average. Pre-app meetings are free and currently scheduling 3–4 weeks out — book one before drawings start.