Subdivisions
This page provides a general overview of land subdivision regulations for cities and counties in Washington State, including subdivisions, short subdivisions, preliminary and final plats, and exemptions.
For a list of key court decisions and attorney general opinions, see our page on Subdivisions Court Decisions and AG Opinions.
New Legislation: Effective June 6, 2024:
- ESHB 2321 modifies provisions for middle housing and minimum residential density requirements, including the definition of major transit stop, the number of types of middle housing certain cities must allow, and exemptions from density requirements for critical areas, lots created through a lot split, and areas on island designated as sole source aquifers.
We have updated this page to reflect the new legislation.
Overview
The subdivision of land into lots is governed in Washington State by chapter 58.17 RCW and by city and county ordinances adopted under that chapter's authority. The following is a list of key terms defined by these statutes.
- Subdivisions are defined in RCW 58.17.020(1) as the "division or redivision of land into five or more lots, tracts, or parcels, sites, or divisions for the purpose of sale, lease, or transfer of ownership."
- Short subdivisions are defined in RCW 58.17.020(6) as the "division or redivision of land into four or fewer lots, tracts, parcels, sites, or divisions for the purpose of sale, lease, or transfer of ownership." Any city or town may increase the number of lots that can be regulated as short subdivisions up to a maximum of nine. Counties planning under the Growth Management Act may do the same with respect to unincorporated land within an urban growth area.
- Plats and short plats are defined in RCW 58.17.020(2) as the maps or representations of subdivisions and short subdivisions respectively that show the division of land into lots and streets, alleys, dedications, easements, etc.
- A Binding Site Plan is an alternative method of land division authorized by RCW 58.17.035. For more information, see Site Plans and Binding Site Plans or Exemptions section below.
Exemptions
Certain land divisions are exempt from state subdivision laws. See RCW 58.17.040.
These exempt divisions include:
- Burial plots;
- Divisions into lots above a certain size;
- Divisions "made by testamentary provisions, or the laws of descent";
- Boundary line adjustments (no additional lots created);
- Divisions for industrial or commercial use when a binding site plan is approved;
- Divisions for leasing lots for mobile homes when a binding site plan is approved; and
- Divisions where a portion of the property is developed as a condominium (and certain other requirements, including a binding site plan, are met).
RCW 58.17.035 authorizes cities and counties to, by ordinance, establish procedures for use of binding site plans as an alternative to the subdivision process for the divisions identified in RCW 58.17.040 that require approval of a binding site plan to be exempt.
Subdivision Process Overview
Subdivisions, other than short subdivisions, must be regulated by cities and counties according to the procedures in chapter 58.17 RCW.
These statutory procedures establish a two-step process for the approval of subdivisions:
- Preliminary plat approval
- Final plat approval
Note that both subdivision and short subdivision approval require compliance with local ordinances such as those dealing with zoning, road standards, shorelines, utilities, and drainage, as set out by RCW 58.17.110.
Preliminary Plats
Initial Review and Hearing
Preliminary plat review is a quasi-judicial process that involves an initial review and hearing by the city or county planning commission or agency, which then makes a recommendation to the city council or board of county commissioners. See RCW 42.36.010 for a definition of quasi-judicial land use actions.
A city or county may establish a hearing examiner system as an alternative to a planning commission or agency hearing and issuing recommendations for preliminary plat approval. See RCW 58.17.330.
Requirements for Approval
Unless the applicant requests otherwise, a preliminary plat must be processed simultaneously with applications for accompanying rezones, variances, planned unit developments, site plan approvals, and similar quasi-judicial or administrative actions to the extent that the procedural requirements for those actions allow for simultaneous processing.
A city or county may not approve a preliminary plat unless the city council, board of county commissioners or county council, or hearing examiner, as the case may be, make written findings regarding certain matters identified in RCW 58.17.110, including open spaces, drainage ways, streets or roads, alleys, other public ways, transit stops, potable water supplies, sanitary wastes, parks and recreation, and playgrounds. Cities must ensure that regulations and conditions for plat approval are consistent with the minimum density requirements in RCW 36.70A.635. Cities and counties must ensure their regulations and conditions for approval are consistent with requirements for allowing accessory dwelling units in RCW 36.70A.680, .681, and .699.
Time Limitations for Approval
Preliminary plats must be approved, disapproved, or returned to the applicant for modification within 90 days of the filing of the preliminary plat application, unless the applicant consents to an extension. This does not include time preparing environmental impact statements. See RCW 58.17.140.
Final Plats
Time Limitations for Submission
RCW 58.17.140 sets out the rules regarding the time period for an applicant to submit a preliminary plat for final plat approval. The general rule is that the applicant has five years after preliminary plat approval in which to submit the plat for final approval. However:
- If the preliminary plat was approved before January 1, 2015, the applicant has seven years to submit a final plat.
- If a preliminary plat was approved before January 1, 2008 and is not subject to the Shoreline Management Act, the applicant has 10 years to file for final plat approval.
Also, a city or county may adopt procedures by ordinance for extensions of these time periods. For examples, see Examples of Subdivisions City and County Codes section.
Approval Process
Final plat approval must be made by the legislative body, or the legislative body may delegate that authority to “an established planning commission or agency, or to such other administrative personnel in accordance with state law or local charter” by ordinance (RCW 58.17.100). The final plat approval is in the nature of a ministerial, non-discretionary process; that is, if the applicant meets the terms of preliminary approval and the plan conforms with state law and local ordinances, final approval must be granted (RCW 58.17.170). There is no public hearing for a final plat approval.
Examples of Ordinances Allowing Administrative Final Plat Approval
Below are ordinances from various Washington jurisdictions amending their municipal code to allow an administrative body or personnel to approve final subdivision plats.
- Auburn Ordinance No. 6654 (2017) – Allows final plat approval by the Planning and Development Department Director
- Spokane County Ordinance No. 2017-1041 (2018) – Allows final plat approval to be delegated administratively
- Yakima Ordinance No. 2017-030 (2017) – Allows the Community Development Director, rather than the city council, to approve final subdivision plats
Requirements for Approval
Among the statutory requirements for final plat approval are:
- Recommendation for approval by the local health department or the agency that would be furnishing sewer and water;
- Approval by the city or county engineer;
- A complete survey; and
- Certification that all taxes and delinquent assessments for the property have been paid.
See RCW 58.17.150, RCW 58.17.160, and RCW 58.17.165.
Time Limitations for Approval
Final plats must be approved, disapproved, or returned to the applicant for modification within 30 days of filing, unless the applicant consents to an extension. See RCW 58.17.140.
Recording and Filing Requirements
Lots in a subdivision cannot be sold until final plat approval is obtained and the plat is recorded with the county auditor. See RCW 58.17.195.
If the county assessor has adopted an "assessor's plat" for the county, before filing with the county auditor, approved final plats must be submitted to the county assessor for "the sole purpose of assignment of parcel, tract, block and or lot numbers." See RCW 58.18.010.
Vesting Rules
RCW 58.17.170(3) sets out the vesting rules for an approved final plat. The lots in an approved final plat are "a valid land use notwithstanding any change in zoning laws" for a period of five years from final plat approval. See RCW 58.17.170(3)(a).
- If the final plat was approved before January 1, 2015, the vesting period is seven years.
- If the final plat was approved before January 1, 2008, it is vested for a period of 10 years from final plat approval.
Also, approved final plats are vested with respect to the conditions of plat approval and with respect to applicable laws for these same time periods, except when "a change in conditions creates a serious threat to the public health or safety in the subdivision." Though, for final plats approved before January 1, 2008, the 10-year vesting period with respect to the conditions of plat approval and to applicable laws applies only if the plat is not within Shoreline Management Act jurisdiction. See RCW 58.17.170(3)(b).
Note that these vesting limitations in RCW 58.17.170(3) do not apply to short plats, which have no vesting limitations. See Noble Manor v. Pierce County (1997).
Short Subdivision Process
No process is set out in state law for approval of short plats. Cities and counties are required by RCW 58.17.060 to adopt by ordinance their own regulations and procedures that provide for "summary approval" of short plats through an administrative process. Regulations and conditions for approval must be consistent with the minimum density requirements in RCW 36.70A.635 and the requirements for allowing accessory dwelling units in RCW 36.70A.680, .681, and .699.
Approval Process
Because it must be an administrative process, there is no public hearing for a short plat application, and the legislative body is not involved in the process. To approve a short plat, the administrative personnel assigned to review short plat applications must make the same written findings in RCW 58.17.110 that are required for subdivision (plat) applications.
Time Limitations for Approval
Short plats must be approved, disapproved, or returned to the applicant for modification within 30 days of the filing of the short plat application, unless the applicant consents to an extension. See RCW 58.17.140.
Recording and Filing Requirements
They must be filed with the county auditor and are not deemed "approved" until such filing. See RCW 58.17.065.
Vesting Rules
There is no limitation on the vesting of an approved short plat as there exists with respect to approved final plats. See Noble Manor v. Pierce County (1997).
Subdivisions City and County Codes
The following codes exemplify how a range of jurisdictions in Washington State have implemented state subdivision law.
City Examples
- Bothell Municipal Code Title 15
- Brewster Municipal Code Title 16
- College Place Municipal Code Title 14.90
- Ferndale Municipal Code Title 17
County Examples
- King County Code Title 19A
- San Juan County Code Ch. 18.70
- Whatcom County Code Title 21
- Yakima County Code Ch. 19.34
Recommended Resources
- Washington State Department of Commerce: MA Short Course on Local Planning Resource Manual (2017) - See section on the platting process.