Can I build a backyard home in Kent?
Since 2023, Washington law lets most city lots hold up to two more homes. Kent writes its own rules on top. Here’s what the code says, in plain English — and a free report on what may fit on your lot.
What Kent allows.
The headline standards. Tap any one for the full wording and the code section.
ADUs per lot2 — 1 attached + 1 detached, 2 attached, or 2 detachedFull wording
2 — 1 attached + 1 detached, 2 attached, or 2 detached (KCC 15.08.350(B)(2)). ADUs count toward maximum density (KCC 15.04.030(10)).
Max size1,000 sq ft gross floor areaFull wording
1,000 sq ft gross floor area (KCC 15.08.350(B)(6)). Excludes areas under 7 ft ceiling height, covered decks and porches up to 200 sq ft total, and any accessory structure the DADU is built within, above or onto.
Max height24 ft for a detached ADUFull wording
24 ft for a detached ADU; chimneys, antennas and railings may extend 4 ft higher (KCC 15.08.350(B)(4)).
Front setback10 ft in NR-S and NR-2 (same as the house)Full wording
Same as principal: 10 ft in NR-S and NR-2 (KCC 15.04.170(E); 15.08.350(B)(3)(a)).
Side setback2 ft for a detached ADU in the rear half of the lotFull wording
2 ft for a detached ADU in the rear half of the lot; on a corner lot, the flanking-street side yard applies. Elsewhere on the lot, the zone side yard of 5 ft in NR-S and NR-2 applies (KCC 15.08.350(B)(3)(c); 15.04.170(F)).
Rear setback2 ft in the rear half of the lot; 0 ft at an unplowed alleyFull wording
2 ft for a detached ADU in the rear half of the lot. It may sit on a lot line abutting a public alley unless the alley is routinely plowed (KCC 15.08.350(B)(3)(c)).
Lot coverage50% maximum site coverage in NR-2Full wording
50% maximum site coverage in NR-2 (45% in NR-S) (KCC 15.04.170(B)).
Parking1 per ADU; none within ½ mile of major transitFull wording
1 space per ADU beyond 1/2 mile walking distance of a major transit stop; 0 spaces within it. The planning director may waive (KCC 15.05.040).
Where a city figure reads stricter than the state floor (RCW 36.70A.681), the floor may control — the report flags it for your parcel.
Living there, selling it, plans, time and fees.
Each answer is the code’s own wording, with the section it comes from. “Not published yet” means the city hasn’t posted a figure — the report asks the city, not the internet.
Are backyard homes allowed?
Yes — attached and detached ADUs are an accessory use in Kent's residential zones, subject to KCC 15.08.350 (KCC 15.04.020; 15.04.030(10); 15.08.350(B)(2)).
Minimum lot size
None for an ADU; zone minimum applies to new lots (KCC 15.04.170)
Do you have to live there?
No — an owner-occupancy covenant is not required, and previously recorded covenants may be released (KCC 15.08.350(B)(9)).
Can it be sold on its own?
Yes — an ADU and the principal dwelling may be designated for separate ownership; condominiums are governed by ch. 64.90 RCW (KCC 15.08.350(B)(11)).
Pre-approved plans
None found
How long the city takes
Not published
Impact fees
The first ADU is exempt from school, transportation, fire and park impact fees; each later ADU pays 50% of the single-family fee (KCC 12.13.040(A)(10); 12.14.070(A)(5); 12.15.040; 12.16.090).
Plans Kent has already approved.
A pre-approved plan skips the design review: Kent has already checked the drawings, so the permit review is about your lot.
Loading the plans…
Pictures are the official pages’ own. A pre-approved plan is not a permit: the city still reviews your site.
The code is half the answer. Your parcel is the other half.
Lines and easements
Where the lot lines really are, which setbacks apply on each side, and whether a utility or access easement takes the corner you had in mind.
Critical areas and slope
Steep slopes, wetlands and streams come with buffers that no citywide number shows. The report reads the county’s maps for your parcel.
Sewer, septic, water, trees
Whether sewer reaches the lot or it’s on septic, where the water service is, and which trees a city protects — the things that decide where a unit can actually go.
What Kent allows, what could fit on your lot, and a planning cost range. If something won’t fit, the report says so — and shows what might.
Where this page comes from.
Read from the Kent municipal code and the city’s own pages on November 5, 2026. The same table feeds the HousUp report, so the report and this page never disagree. Cities amend their codes; before you design anything, confirm the current wording with the city.
2 sources, read November 5, 2026
Find out what your property could become.
Type your address. Within a few hours: what Kent allows, what could fit, and a planning cost range. Free, no obligation.