Can I build a backyard home in Kenmore?
Since 2023, Washington law lets most city lots hold up to two more homes. Kenmore 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 Kenmore allows.
The headline standards. Open any card for the full wording and the code section.
ADUs per lot2 per lot, attached or detached in any combinationFull wording
2 per lot, attached or detached in any combination (KMC 18.73.100.A). Unit-lot density counts ADUs as units — base 2 units per parent lot in R-4/R-6, 4 within one-quarter mile walking distance of a major transit stop or with an affordable unit (KMC 18.21.030 Table B fn 18)
Max sizeAttached 1,000 sq ft; detached up to 17% of the lot, max 1,500 sq ftFull wording
Attached: 1,000 sq ft — 'An attached accessory dwelling unit shall not exceed a floor area of 1,000 square feet' unless using preexisting single-level floor area (KMC 18.73.100.D.1). Detached: lots of 6,000 sq ft or more, 17% of lot area up to 1,500 sq ft; lots under 6,000 sq ft, 1,000 sq ft (KMC 18.73.100.D.2)
Max height35 ftFull wording
35 ft — 'The maximum height for a detached ADU shall be 35 feet'; one story over a detached garage or two stories at ground level (KMC 18.73.100.E); zone maximum 35 ft in R-4/R-6 (KMC 18.21.030 Table B)
Front setback15 ft street setback in R-4/R-6Full wording
15 ft street setback in R-4/R-6; 10 ft with alleys or townhouses (KMC 18.21.030 Table B fn 8); ADUs 'must meet the bulk development standards applicable to the principal unit' (KMC 18.73.100.C)
Side setback5 ft minimum each side, 15 ft combined (0 ft at an alley)Full wording
'Any side yard shall equal a minimum of five feet but the two side yards combined must equal a minimum of 15 feet.' (KMC 18.21.030 Table B fn 11); a DADU may sit 'at a property line with no setback' where the line abuts a public alley (KMC 18.73.100.I)
Rear setback20 ft in R-4/R-6Full wording
20 ft in R-4/R-6 (KMC 18.21.030 Table B); 0 ft for a DADU on a property line abutting a public alley (KMC 18.73.100.I)
Lot coverageImpervious: R-4 45–55%, R-6 60–70%Full wording
No building-coverage standard; impervious surface: R-4 base 45% / max 55%, R-6 base 60% / max 70% (KMC 18.21.030 Table B; fn 14: base may be exceeded up to the max with approved low-impact development)
ParkingNoneFull wording
None — 'No additional off-street parking spaces shall be required for an ADU.' (KMC 18.73.100.F)
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 — 'Up to two accessory dwelling units, either as attached or detached accessory dwelling units' are allowed 'in all areas which permit single-family development' (KMC 18.73.100.A, Ord. 25-0630); accessory use under KMC 18.21.020 Table A (fn 19: no CUP)
Minimum lot size
None — 'No minimum lot size is required for an ADU.' (KMC 18.73.100.B). Zone minimums: R-4 7,200 sq ft, R-6 5,400 sq ft (KMC 18.21.030 Table B)
Do you have to live there?
No — KMC 18.73.100 (Ord. 25-0630) has no owner-occupancy provision; a recorded notice identifying the unit as accessory is required (KMC 18.73.100.G)
Can it be sold on its own?
Yes — 'Accessory dwelling units may be sold individually from the principal unit.' (KMC 18.73.100.L)
Pre-approved plans
None — the city ADU page lists Checklists #403 (DADU) and #407 (attached ADU) and online application only (2026-10-08) — confirm with city
How long the city takes
Not published — the Permits & Inspections page describes the steps without timelines; applications through MyBuildingPermit; ask [email protected] for the current estimate (https://kenmorewa.gov/government/departments/development-services/permits)
Impact fees
ADUs exempt from transportation, park and school impact fees — KMC 20.47.040(A)(7) 'Accessory dwelling units' (fees assessed if the unit is later converted). Caution: KMC 20.47.020 defines an ADU as attached/within the primary dwelling — confirm the exemption is applied to detached units. Resolution 23-400 waives building-permit fees for new ADUs (in the 2026 fee schedule per the city ADU page)
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 Kenmore 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 Kenmore municipal code and the city’s own pages on October 9, 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.
- www.kenmorewa.gov/government/departments/development-services/permits/accessory-dwelling-units-adus
- ecode360.com/49603662 (KMC 18.73.100)
- ecode360.com/49600538 (KMC 18.21.030)
- ecode360.com/49601378 (ch. 18.40)
- ecode360.com/49609887 (KMC 20.47.020–.040)
- www.kenmorewa.gov/government/departments/development-services/maps
- kenmorewa.gov/government/departments/development-services/permits
- RCW 36.70A.681 — the state floor for accessory dwelling units
Find out what your property could become.
Type your address. Within a few hours: what Kenmore allows, what could fit, and a planning cost range. Free, no obligation.