Can I build a backyard home in Kirkland?
Since 2023, Washington law lets most city lots hold up to two more homes. Kirkland 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 Kirkland allows.
The headline standards. Open any card for the full wording and the code section.
ADUs per lot2 per single-family dwellingFull wording
2 per single-family dwelling (1 attached + 1 detached, or two of either); 1 in the Residential-L Shoreline Environment
Max size1,200 sq ft gross floor areaFull wording
1,200 sq ft gross floor area; the director may allow more for single-level attached conversions
Max heightThe zone’s single-family heightFull wording
Must conform to the single-family standards of the zone; converted existing structures are exempt where the nonconformity is not increased
Front setbackThe zone’s single-family standardsFull wording
Single-family standards of the zone
Side setbackThe zone’s single-family standardsFull wording
Single-family standards of the zone
Rear setbackThe zone’s single-family standardsFull wording
Single-family standards of the zone
Lot coverageThe zone’s single-family standardsFull wording
Single-family standards of the zone
ParkingNone near major transit; otherwise 1 space for the first ADU (exceptions apply)Full wording
None within 1/2 mile of a major transit stop; otherwise 1 space for the first ADU unless there is on-street parking within 600 ft or frequent transit
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
Minimum lot size
Zone minimum applies
Do you have to live there?
No — removed
Can it be sold on its own?
Yes — an ADU may be segregated in ownership, and a DADU can be placed on its own lot through a unit lot subdivision under KMC Title 22
Pre-approved plans
Yes — the Kirkland ADU Toolkit's 'Registered Pre-Approved Plan' gallery (The Schooner by Fivedot, Cedar Cottage and Sedge Cottage by Cast Architecture, The Family by Ahouse Studio, 'growing'): choose a plan, license it from the designer (up to $1,000), adapt it to the lot, submit through MyBuildingPermit as 'Pre-Approved Detached Accessory Dwelling Unit'; review 'may be as little as a few weeks, compared to approximately three months'; no permit-fee reduction stated (https://www.kirklandwa.gov/Government/Departments/Planning-and-Building/Housing/The-Kirkland-ADU-Toolkit, read 2026-10-08)
How long the city takes
As little as a few weeks with a pre-approved plan, per the city
Impact fees
Transportation, park and fire impact fees on an ADU 'will not be greater than fifty percent of the impact fee that would be imposed on the principal unit' (KMC 27.04.030(m), 27.06.030(l), 27.10.030(l)); an attached ADU is counted with the single-family dwelling for the fire-fee cap (27.10.030(m)). School impact fees: building permits for a legal ADU approved under Title 23 are exempt (KMC 27.08.050(a)(2)). The city's ADU pages do not state fee treatment
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 Kirkland 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 Kirkland 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.
- kirkland.municipal.codes/KZC/115.07
- www.kirklandwa.gov/Government/Departments/Planning-and-Building/Housing/The-Kirkland-ADU-Toolkit/ADU-Regulations
- kirkland.municipal.codes/KMC/27.04.030
- kirkland.municipal.codes/KMC/27.06.030
- kirkland.municipal.codes/KMC/27.08.050
- kirkland.municipal.codes/KMC/27.10.030
- RCW 36.70A.681 — the state floor for accessory dwelling units
Other places in King County.
Find out what your property could become.
Type your address. Within a few hours: what Kirkland allows, what could fit, and a planning cost range. Free, no obligation.