Kirkland has embraced Accessory Dwelling Units (ADUs) as an important housing option, making it easier for homeowners to create flexible living spaces while increasing the long-term value of their property. Whether you're planning a detached backyard cottage (DADU) or an attached ADU, Kirkland's updated regulations provide more opportunities than ever before—but every property is still unique.

Understanding the City's development standards before beginning architectural design can save significant time, reduce unexpected costs, and help you make informed decisions throughout the permitting process.

Many residential properties in Kirkland may qualify for up to two ADUs, allowing homeowners to choose an attached ADU, a detached backyard cottage, or a combination of both where permitted.

These changes create new opportunities for:

• Long-term rental income
• Housing for aging parents
• Adult children returning home
• Multigenerational living
• Guest accommodations
• Increased property value

The best solution depends on your property's size, zoning, and long-term goals.

Kirkland allows ADUs up to 1,200 square feet, subject to current zoning and development standards.

This larger size gives homeowners greater flexibility to create comfortable one- and two-bedroom floor plans while maintaining neighborhood character. Because allowable size depends on several development standards, verifying your property early in the planning process remains an important first step.

One of Kirkland's unique advantages is its library of pre-approved detached ADU plans.

These professionally designed plans can reduce architectural costs and shorten the design process for homeowners who find a floor plan that fits their needs. While every property still requires site-specific review, using a pre-approved plan can often simplify the permitting process.

Kirkland no longer requires homeowners to live in either the primary residence or the ADU.

Recent housing reforms also provide additional ownership flexibility through approved ownership options where applicable. These changes make ADUs a more practical long-term investment while expanding housing opportunities throughout the community.

Although Kirkland has simplified many ADU regulations, every property must still comply with current development standards. These requirements vary depending on zoning district, lot configuration, and individual site conditions.

Many homeowners already have an existing detached garage or accessory building that may be suitable for conversion into an ADU. Converting an existing structure can often reduce construction costs while making efficient use of your property. Existing buildings must still comply with current structural, energy, fire, and life-safety codes.

City regulations provide general development standards, but they cannot answer every question about your specific property. These property-specific conditions frequently have a greater impact on project cost than the zoning regulations themselves.

The most successful ADU projects begin with understanding the property before investing in architectural drawings.

Our feasibility study evaluates zoning, setbacks, utilities, site constraints, and expected construction costs before design work begins. This gives homeowners a clear understanding of what can realistically be built and helps avoid expensive redesigns later in the process.

At DADU Solutions, our philosophy is simple:

Know Before You Build.

Our goal is to help homeowners make informed decisions with confidence by understanding their property first, creating a smoother path from feasibility to permitting and construction.