Background

The City of SeaTac is updating its zoning regulations to allow and regulate Co-Living Housing. Co-living is a type of housing where residents rent individual sleeping units and share common facilities such as kitchens and laundry rooms. This form of housing provides additional affordable and flexible living options, particularly for individuals who do not need, or cannot afford, a multi-family apartment.

In 2024, the Washington State Legislature adopted House Bill (HB) 1998, which requires cities to allow co-living housing on all lots allowing at least six multi-family or middle housing units. SeaTac’s amendments will implement this requirement while ensuring that co-living developments are designed to be compatible with surrounding neighborhoods and consistent with the City’s Comprehensive Plan housing goals.

What is Co-Living Housing?

Co-living is a type of housing where residents rent individual sleeping units. Each unit is lockable and provides living and sleeping space. Residents share common facilities such as kitchens, laundry rooms, and open space within the building.

Examples of co-living buildings in Redmond and Seattle. Source: MAKERS.

HB 1998 Requirements

In 2024, the Washington State Legislature adopted House Bill (HB) 1998, which requires all cities planning under the Growth Management Act (GMA) to allow Co-Living Housing.

Key requirements of HB 1998 include:

• Definition of Co-Living Housing – Cities must recognize co-living as a distinct housing type. A co-living building contains sleeping units with shared kitchens and other common facilities.
• Permitted Use – Co-living must be allowed in any zone where at least six multi-family or middle housing units are allowed.
• Development Standards – Cities may adopt reasonable regulations related to building and site design (e.g., kitchens, laundry, open space, and parking), but they cannot effectively prohibit co-living or make the regulations more stringent than for multi-family.
• Affordable Housing Incentives – Co-living must qualify for the same incentive programs as multi-family housing, such as the Multi-family Tax Exemption (MFTE) program.

SeaTac’s code amendments implement these requirements while tailoring standards to local conditions, including the City’s proximity to the airport and its unique housing needs.

What is Being Proposed?

The proposed code amendments will:

• Create a new definition for Co-Living Housing.
• Establish development standards for co-living, including requirements for kitchens, laundry rooms, open space, and building layout.
• Set parking standards specific to co-living, including adjustments within the 1-mile airport buffer.
• Clarify that co-living qualifies for the Multi-family Tax Exemption (MFTE) and affordable housing incentives.
• Adjust density calculation provisions so that co-living can be measured consistently with multi-family housing.
• Update the land use chart to identify which zones will allow co-living housing, and under what conditions.
• Prohibit the use of co-living sleeping units as short-term rentals.

Frequently Asked Questions

What is Co-Living Housing?
Co-living is a type of housing where residents rent individual sleeping units. Each unit is lockable and provides living and sleeping space. Residents share common facilities such as kitchens, laundry rooms, and open space within the building.

How is co-living different from multi-family housing?
In a typical apartment building, each unit has its own kitchen, bathroom, and living space. In co-living, residents share kitchens and other common facilities. The important differentiating factor between co-living and multi-family housing is that co-living sleeping units cannot contain a kitchen. This arrangement allows for smaller private spaces and lower rents.

Where will co-living be allowed in SeaTac?
Co-living housing will be allowed in several residential and commercial/mixed-use zones. The proposed code amendments identify the specific zones and whether co-living will be an outright or conditional use.

How will parking be handled?
The code amendments create parking standards tailored to co-living. These are generally lower than for multi-family housing, reflecting the smaller unit sizes and different demographics of residents.

Will co-living units be allowed as short-term rentals?
No. The proposed code amendments prohibit co-living sleeping units from being used as short-term rentals. Co-living housing is intended to provide long-term housing options.

Why is the City updating the code now?
In 2024, the Washington State Legislature passed HB 1998, requiring cities to allow co-living housing. Updating the code ensures SeaTac complies with state law while creating local standards that reflect the City’s goals for housing choice, affordability, and neighborhood compatibility.

Meeting Information

View meeting packet information for the Planning Commission (PC), Planning & Economic Development (PED), or Council Committee Meetings by clicking on the appropriate link provided in the table below.

Planning Commission Meeting – May 20, 2025

Planning Commission Meeting – July 15, 2025

Planning Commission Public Hearing – October 7, 2025

Planning and Economic Development Meeting – November 20, 2025

City Council Meeting – December 9, 2025

Draft Code

Public Hearing Draft Code

Additional Information

Planning for Middle Housing – Washington State Department of Commerce

Co-Living User Guide and Model Ordinance

Contact Information

Laura Stilwell, Associate Planner

206-973-4833

lstilwell@seatacwa.gov