You live in Kirkland and have room behind the house for a small cottage. Can you build one? On most lots, yes, and the city even keeps a gallery of pre-approved DADU plans. Kirkland DADU requirements come from the Kirkland Zoning Code, though, so a Seattle checklist will miss the shoreline limits, the parking test and the recorded covenant.

A DADU is a detached accessory dwelling unit, a separate small home on the same lot as a house. Details below reflect official City of Kirkland pages checked in October 2026. Confirm with city staff for your property.

Where the Rules Live

Kirkland regulates ADUs in section 115.07 of its Zoning Code. In October 2026, the online code noted that Ordinance 4948 had amended the section and was pending codification. The city also keeps a plain language ADU regulations page in its ADU toolkit.

Read both sources, because the summary page points back to code sections, and the code itself controls when the two seem to differ.

How Big and How Many?

Kirkland caps an ADU at 1,200 square feet of gross floor area, while Seattle allows 1,000 square feet for a unit with up to two bedrooms. Area under five feet of ceiling height does not count. The Planning and Building Director may allow more for an attached unit that fills a single floor of the existing house.

Most lots may hold two ADUs, both attached, both detached or one of each. A detached unit must sit in its own structure and may not share a common roof with the main house. The city asks anyone planning two attached units to call for building code help.

Setbacks, Coverage and Conversions

Every ADU must meet the setbacks, height limits and lot coverage that apply to a single family home in that zone. If the existing house is large, little room may remain, so a site plan helps.

Older buildings get some help. Converting an existing structure, such as a detached garage, is exempt from current setback and lot coverage rules if the work does not increase the nonconformity.

Shoreline Lots Follow Extra Rules

Lakefront property has its own limits. The regulations page says a lot in the Residential L Shoreline Environment may have only one ADU, not two. On those lots and in the M/H Shoreline Environment, a DADU must sit landward of the main residence.

Ownership shifts here too. Elsewhere in Kirkland the code lets an owner split an ADU from the house in ownership, but Residential L shoreline lots are the exception. The post on whether a DADU can be owned or sold separately covers the broader question.

Do I Need a Parking Space?

It depends on transit. The code waives off-street parking within one-half mile of a major transit stop, which the city currently names as the STRIDE I-405 bus rapid transit station. Stops on the RapidRide K Line will count once construction is underway.

Farther out, the code can require one space. Two exceptions apply: on-street parking within 600 feet, or a lot within one-half mile of transit with 15 minute headways at commute times. Seattle does not require parking for ADUs, so this is a real difference.

The Recorded Covenant

Kirkland asks for an ADU permit application with an affidavit signed by the owner. Its registration form includes a property covenant that the owner files for recording with the King County Recorder’s Office. That covenant runs with the land as long as the unit remains.

Build this step into your paperwork plan. Staff can tell you which form applies to your project.

Permits and Stock Plans

Kirkland handles ADU permits through MyBuildingPermit, where you submit plans, track review and schedule inspections. The city’s ADU permitting process page lists what a pre-approved plan submittal needs. Items include a site plan with the plan registration ID, an ADU registration application, a plumbing worksheet and a survey in most cases.

Projects near lakes, streams, slopes or wetlands may need further review. A geotechnical report may apply, and the post on how soil conditions affect foundations explains why. After final inspection, the city issues a certificate of occupancy, and an owner who rents the unit needs a business license.

A Hypothetical Houghton Lot

Consider an invented owner on a Lake Washington lot in Houghton. Her parcel carries the Residential L shoreline designation, and she hoped for two cottages. With that designation she is limited to a single unit, placed landward of the house and away from the water.

She also learns that separate sale is off the table there. Her plan shifts to one detached cottage behind the house, sized well under 1,200 square feet.

Common Surprises

• A shoreline designation that allows only one ADU
• Parking required on lots far from frequent transit
• A covenant that must be recorded with the county
• Extra review near slopes, streams or wetlands

Before You Design

• Check for any shoreline environment on your parcel.
• Measure the walking distance to STRIDE and frequent transit.
• Order a survey, as the post on why a property survey matters explains.
• Ask whether Ordinance 4948 affects your plan.
• Pick a pre-approved plan or a custom design.

FAQ

How large can a Kirkland ADU be?

The cap is 1,200 square feet, measured as gross floor area. Low space under the roof framing is left out. For an attached unit filling one floor of the existing home, the Director may allow more. A detached unit must also meet the height and coverage limits for the zone.

Does Kirkland offer stock DADU plans?

Yes. Kirkland publishes city-reviewed plans you can license from the designer, and the submittal must include the plan registration ID on the site plan. Expect to add a survey and any reports your lot requires.

Can I sell a Kirkland ADU separately?

On most lots, yes, since the code lets an ADU be owned separately and a DADU can sit on its own unit lot. The exception is the Residential L shoreline area, where the city does not allow it.

Check the Shoreline Map and Transit Distance

Two questions shape most Kirkland plans: is the lot in a shoreline environment, and how far is it from qualifying transit? Answer both before choosing a plan. Other cities are covered in the Greater Seattle ADU rules category, which shows how Kirkland DADU requirements compare.