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King County Comprehensive Plan: Four to One Program


The King County Four‑to‑One Program is an innovative land use management technique authorized under the Washington State Growth Management Act[i] that seeks to create a continuous band of open space along the urban growth area boundary and prevent sprawl. Since the inception of the program, about 360 acres have been added to the urban growth area while nearly 1,400 acres of permanent open space have been conserved.

The Four‑to‑One Program is guided by policies and rigorous criteria in the Countywide Planning Policies, Comprehensive Plan, and King County Code. For properties that meet the criteria, the program allows willing land owners to voluntary apply to have their land considered, with twenty percent of the land (i.e., the "one") potentially added to the urban growth area and the remaining eighty percent (i.e., the "four") permanently added to the King County Open Space System. Four-to-One projects are approved at the discretion of the County as part of an update to the Comprehensive Plan.

Summary of Four-to-One Program and Provisions

For site specific land use changes such as Four-to-One proposals, Docket Requests are referred to the second step, which is the process for obtaining a site‑specific land use amendment.[iii] A site‑specific amendment application requires a filing fee and review by the King County Hearing Examiner. The Hearing Examiner sends recommendations to the King County Council for consideration during the annual Comprehensive Plan amendment process.

General Provisions

  • King County evaluates proposal for quality open space and the feasibility of urban development; only the highest quality proposals are recommended as amendments to Comprehensive Plan
  • Four-to-One proposals are allowed on the annual Comprehensive Plan cycle; Four-to-One proposals are one of only three ways to amend the Urban Growth Area boundary
  • Through the Four‑to‑One Program, King County shall actively pursue dedication of open space along the original Urban Growth Area line adopted in the 1994 King County Comprehensive Plan
  • Total new urban land under Four-to-One Program shall not exceed four thousand acres
  • The minimum parcel size is twenty acres; smaller parcels can be combined to meet the minimum

Procedural Issues (and overview of the typical Four‑to‑One Process)


  • Typically, a Docket is submitted by a property owner requesting consideration of a Four-to-One proposal

Initial Review

  • The Office of Performance, Strategy and Budget reviews the Docket Request for eligibility and policy-level issues; eligible proposals are referred to DPER for processing as a Site Specific Land Use Map Amendment
  • The review is based on the criteria in the Comprehensive Plan and King County Code (described more fully below)
  • Review includes meetings with proponent, site and area assessment, policy analysis
  • Proposals that are adjacent to cities or potential annexation areas are referred to the affected city as well as service providers such as special purpose districts for review and recommendation
  • The adjacent city needs to agree to add the new urban land to their potential annexation area; some cities require annexation prior to development

Docket Process

  • Recommendation in Docket Report, transmitted to County Council on last business Day in April
  • For proposals where the Executive recommendation is negative, the proponent can work with Council to move the proposal forward in a future Comprehensive Plan update
  • For proposals where the Executive recommendation is positive, the proponent can pursue it through the site‑specific land use map amendment process

Site Specific Land Use Map Amendment

  • The Site Specific Land use Map Amendment process is used to establish site suitability and development conditions for both the urban and rural portions of the proposal.  Key steps in this process include:
    • Pre-Application Meeting
    • Property owner submits a detailed application
    • Review by a multidisciplinary technical team on land use, environmental, open space, transportation and other issues
    • Following review and SEPA analysis, lead departments (DPER and PSB), develop County position on proposal[v] and issue recommendation
    • Transmittal of recommendation to Hearing Examiner for review, public hearing and decision (to be issued for consideration in a future Comprehensive Plan review by Council)
  • Following Hearing Examiner process, this may be added to the Scope for a future Comprehensive Plan update

Comprehensive Plan Process

  • Comprehensive Plan analysis by Executive in a Public Review Draft (potentially with community meetings) and in Executive Recommended Plan that is transmitted to Council
  • County Council review in Committee, public hearing, and release of Council Committee draft Plan
  • All Urban Growth Area boundary amendments, including Four‑to‑One proposals, that are included in the Council Committee draft Plan are transmitted to the Growth Management Planning Council for review and recommendation to the County
  • Full County Council action on the Comprehensive Plan, including Four‑to‑One proposals. Four-to-One proposals are adopted as a land use amendments, with a term conservation easement placed on the open space portion, when the Council approves proposal; the easement is recorded as a property‑specific development condition (i.e., a "P‑Suffix" condition)


  • Open space permanently dedicated to King County in fee simple upon final plat approval
  • Applicant moves project towards implementation, including submission and approval of a final Plat and ultimately, building permits and development

If applicant does not pursue urban development or fails to record final plat prior to expiration of preliminary plat approval, urban properties restored to rural during next comprehensive plan update and the conservation easement is removed

Proposed new urban lands

  • Urban services, and follows topographical features and/or natural boundaries to allow for efficient urban service provision
  • The land is contiguous to 1994 adopted urban growth area boundary, with minor exceptions allowed for critical areas and park/open space lands
  • Proposals are evaluated using the following criteria: fish and wildlife habitat and networks and habitat for endangered and threatened species; open space connections; wetlands, stream corridors, ground water and water bodies; unique natural, biological, cultural, historical or archeological resources; size of open space dedication and connection to other open space dedications along the urban growth area boundary
  • The new urban land shall have a minimum density of 4‑dwelling units per acre, be served directly (i.e., without crossing open space or rural area) by sewers and other efficient urban services and facilities
  • The new urban land is limited to residential development
  • Land is sufficiently free of environmental constraints in order to allow urban densities
  • Drainage facilities to serve the new urban land shall be located in the urban portion of the site
  • Roads serving the new urban land shall not be counted as required open space

Proposed new open space lands

  • The new open space land preserves high quality habitat, critical areas or unique features that contribute to a band of permanent open space along edge of the urban growth area
  • Proposals are evaluated using the following criteria: quality of habitat, connections to regional open space, protection of water resources, unique features, generally configured to connect with adjacent open space; size and connection along UGA
  • The new open space land is dedicated to King County at final formal plat recording
  • The new open space land retains its Rural Area designation and is used primarily for natural area or passive recreation site purposes and not for urban‑serving facilities
  • The new open space land should be configured to connect with open spaces on adjacent properties with at least a portion of open space surrounding the new urban land
  • The minimum depth of the new open space land shall be one‑half of the buffer width, with minor exceptions, and generally follow the existing urban growth area boundary
  • Other minor uses are allowed on the new open space land

Resource Lands

  • Four-to-Ones cannot redesignate existing Resource Lands to new urban land
  • The new open space lands can be zoned to Resource Lands and used for farming or forestry


  • Affordable housing may be required in some projects
  • A mix of housing types including thirty percent below‑market‑rate units to be included in projects 200 acres or greater; projects that exceed thirty percent can have their open space dedication reduced

Property owners interested in submitting a Four‑to‑One proposal should familiarize themselves with aforementioned aspects of the program, review the enabling policies and criteria and, following this, contact the staff noted on this webpage.




[i]   36.70A.090 Revised Code of Washington

[ii]   Four‑to‑One proposals have also been included in the Scope of Work Motion for an update of the Comprehensive Plan by the County Council.  In these cases, unless the property owners have a clearly defined proposal, the review may be at the policy‑level and focus on determining eligibility and defining County interests for when an actual proposal is developed and submitted.

These Four-to-Ones are evaluated through the Area Zoning and Land Use Study process (20.18.030.B.8) which involves departmental review, communication with proponent, notification to surrounding area residents and stakeholders, a recommendation in the Public Review Draft of the Comprehensive Plan (released in the fall), public comment period and public meetings, and a final recommendation in the Executive Recommended Plan (released in March).  Then, the Council considers the requested change in the Comprehensive Plan for adoption (adopted in fall to winter).  While these proposals are initiated and follow a slightly different review path, they are finalized in the same manner as a property-owner initiated Four-to-One, and require a Preliminary Formal Plat Approval, and placement of a Term Conservation Easement when the County Council approves the proposal as a Land Use amendment (with specific conditions codified as property-specific development conditions (i.e., a "P Suffix" condition) to the Comprehensive Plan.

[iii]   King County Code 19A.04.260 and 19A.08.150.  Note: The Four‑to‑One program requires the adjacent jurisdiction to agree to add the new urban portion of the site to its potential annexation area (CPP DP‑17a).  This means the urban portion of the site may be annexed before development occurs and, if this is the case, the final plat approval will be processed by the city/town, not the County.

[iv]   Primary provisions are found at Countywide Planning Policy DP‑16 and DP‑17, Comprehensive Plan Policy U‑185 to U‑190 and King County Code 20.18.170 to 20.18.180. Other sections of policy and code that reference Four to One include 20.18.030, 20.18.040, 19A.12.020, 19A.12.040

[v]  The last four to one proposal was processed in 2015. Based on this process, the review involves a shared responsibility between the Regional Planning Unit in the Office of Performance, Strategy and Budget which leads the policy and intergovernmental analysis, and the Department of Permitting and Environmental Review (DPER), which leads the technical analysis of the preliminary plat.  This involves coordination with other departments such as the DNRP (the Department of Natural Resources and Parks) on the open space elements of the proposal, DCHS (the Department of Community and Human Services) on any affordable housing elements of the proposal, DOT (Department of Transportation) on any transportation related elements of the proposal, and others. PSB (the Office of Performance, Strategy and Budget) also leads the policy analysis related to consistency with the Countywide Planning Policies and Comprehensive Plan, and review by the Growth Management Planning Council.