Kent ADU rules
✓ Verified against code · August 19, 2026
Current rules under KCC 15.08.350 (Kent City Code), adopted by Ordinance 4517 (building on Ord 4464), in effect since July 30, 2025. Kent's ADU rules came in two waves — a 2023 liberalization (Ord 4464) and the ReCode Kent package effective July 30, 2025 (Ord 4517) — with the zone charts reworked again in April 2026 (Ord 4536). ReCode phases are still in progress, so this code is actively moving.
Common questions, answered from the code
What do impact fees cost on a Kent ADU?
For your first ADU: nothing — it's exempt from school, transportation, and park impact fees. A second ADU pays 50% of the single-family rate in each category. That first-unit exemption is one of the best ADU fee deals in Puget Sound.
KCC 12.13.040(A)(10); 12.14.070(A)(5); 12.16.090(B)(3) · Permalink
How close to the property line can a Kent DADU sit?
In the rear half of the lot, within 2 feet of the side and rear lines — and on the lot line itself where it abuts an unplowed public alley. That's tighter siting than nearly any neighboring city allows.
KCC 15.08.350(B)(3) · Permalink
How big can a Kent ADU be?
1,000 sq ft each, and the exclusions matter: low-ceiling areas, up to 200 sq ft of covered porch or deck, and — if you build a DADU into or above an existing garage — the garage's own floor area doesn't count against you.
KCC 15.08.350(B)(6) · Permalink
Do I have to live on the property?
No — Kent's code goes out of its way to say an owner-occupancy covenant is not required, and if you recorded one under the old rules, the planning director can release it.
KCC 15.08.350(B)(9) · Permalink
Can I sell a Kent ADU separately?
Yes — separate ownership, including condominiumization, is expressly allowed by the code.
KCC 15.08.350(B)(11) · Permalink
The rules at a glance
| ADUs allowed per lot | Two ADUs per lot, in any mix — one attached plus one detached, two attached, or two detached. An ADU connected to the house only by a breezeway or shared roof (or attached to a garage) counts as detached.KCC 15.08.350(B)(1)–(2) |
| Maximum size | 1,000 sq ft per ADU (no transferring square footage between the two). Excluded from the count: areas under 7-ft ceilings, up to 200 sq ft of covered decks and porches, and the host structure's floor area when the DADU is built within, above, or as an addition to an existing garage or accessory building.KCC 15.08.350(B)(6) |
| Detached ADU height | 24 ft; chimneys, antennas, and railings may extend 4 ft above that.KCC 15.08.350(B)(4) |
| Detached ADU setbacks | Zone setbacks apply generally — but a DADU in the rear half of the lot may come within 2 ft of the side and rear lot lines, and may sit on the lot line where it abuts a public alley (unless the alley is routinely plowed). The planning director may modify setbacks where lot shape makes an ADU infeasible.KCC 15.08.350(B)(3)(a)–(d) |
| Off-street parking | Zero within a half-mile walking distance of a major transit stop; one space per ADU beyond that, with director waivers available for special circumstances.KCC 15.05.040(A) parking chart (rev. 1/26) |
| Owner-occupancy | None — the code affirmatively states an owner-occupancy covenant 'is not required,' and old recorded covenants can be released by the planning director (applicant pays the recording cost).KCC 15.08.350(B)(9) |
| Lot coverage / floor area | Underlying zone standards apply (maximum site coverage runs 30–55% by residential zone under the April 2026 charts). Note: ADUs count as dwelling units in Kent's density calculations.KCC 15.08.350(B)(8); 15.04.170 (Ord 4536) |
| Permit path & timeline | An ADU permit through Economic & Community Development plus the building permit; attached and internal ADUs in existing homes are exempt from residential design review. No published review timeline.KCC 15.08.350(B)(10); 15.04.180(10) |
Worth knowing
- The first ADU is exempt from school, transportation, and park impact fees (treated as part of the single-family use); each subsequent ADU pays 50% of the single-family rate — all three verified in current code text.
- No metal, aluminum, or fiberglass siding on ADUs — an unusual materials rule.
- Separate ownership/condominiumization of ADUs is expressly allowed.
- Existing nonconforming structures — including garages violating setbacks — may be converted to ADUs.
- A shared water meter with the main house is permitted if a shared-meter notice is recorded with King County before permit issuance.
- The rear-half-of-lot 2-ft setback allowance is among the tightest DADU siting rules in the region.
On our watchlist
ReCode Kent Phases 2.5 and 3 are in progress (Phase 3 includes Mill Creek Historic District standards) — we re-check KCC 15.08.350 each pass while the package moves.
No published permit review timeline found; unverified.
Check your parcel
The rules above are citywide — what you can build depends on your lot’s zone, size, and setbacks. Look yours up on the official viewers:
- King County Parcel Viewer
- King County Assessor Property Search (eRealProperty)
- Kent Zoning & Future Land Use map
Primary sources
Other Washington cities
Bellevue · Bothell · Burien · Edmonds · Everett · Issaquah · Kirkland · Lynnwood · Olympia · Redmond · Renton · Sammamish · Seattle · Shoreline · Tacoma
Not legal advice. Every fact above cites the code section it comes from — check the cite, or ask your city’s planning department to confirm your specific lot. Spotted an error or a new ordinance? See about to reach us; corrections are logged in the changelog.