Growth Management Act.  
The Growth Management Act (GMA) is the comprehensive land use planning framework for counties and cities in Washington.  The GMA establishes land use designation and environmental protection requirements for all Washington counties and cities.  The GMA also establishes a significantly wider array of planning duties for 28 counties, and the cities within those counties, that are obligated to satisfy all planning requirements of the GMA.  These jurisdictions are sometimes said to be fully planning under the GMA. 

All jurisdictions are required by the GMA to designate natural resource lands and to designate and protect critical areas.  These protection requirements obligate local governments to adopt development regulations, also known as critical areas ordinances, that meet specified criteria.  As defined by statute, critical areas include:  wetlands, aquifer recharge areas, fish and wildlife habitat conservation areas, frequently flooded areas, and geologically hazardous areas. 

The GMA also directs fully planning jurisdictions to adopt internally consistent comprehensive land use plans.  Comprehensive plans are implemented through locally adopted development regulations, and both the plans and the local regulations are subject to review and revision requirements prescribed in the GMA.  When developing their comprehensive plans, counties and cities must consider various goals set forth in statute.  

Growth Management Act—Housing Element.
Each comprehensive plan must include a housing element.  The housing element must ensure the vitality and character of established residential neighborhoods and, among other requirements must include an inventory and analysis of existing and projected housing needs that identifies the number of housing units necessary to manage projected growth, including emergency housing, emergency shelters, and permanent supportive housing.

Growth Management Act—Increased Housing Capacity.
The adoption of ordinances, amendments to development regulations, and other nonproject actions taken by a city to implement certain actions related to increasing housing supply are not subject to administrative or judicial appeal under the State Environmental Policy Act (SEPA) if the adoption occurs prior to April 1, 2023.  These actions include, among others:

• authorizing cluster zoning or lot size averaging in all zoning districts that permit single-family residences;
• authorizing a duplex on each corner lot within all zoning districts that permit single-family residences; and
• removing owner occupancy requirements related to accessory dwelling units.

State Environmental Policy Act.
The SEPA establishes a review process for state and local governments to identify environmental impacts that may result from governmental decisions, such as the issuance of permits or the adoption of land use plans.  The SEPA environmental review process involves a project proponent or the lead agency completing an environmental checklist to identify and evaluate probable environmental impacts. 

Government decisions that the SEPA checklist process identifies as having significant adverse environmental impacts must then undergo a more comprehensive environmental analysis in the form of an Environmental Impact Statement.  Decisions made under SEPA may generally, although not always, be appealed, first at the administrative level, and then at the judicial level. 

A project action evaluated under SEPA by a city, county, or town planning fully under the GMA is exempt from appeals under SEPA on the basis of the evaluation of or impacts to transportation elements of the environment, so long as the project does not present significant adverse impacts to state highways as determined by the Department of Transportation and the project is:

• consistent with either a locally adopted transportation plan or the transportation element of a comprehensive plan; and
• consistent with the transportation element of a comprehensive plan, and either a project for which traffic or parking impact fees are imposed pursuant to, or a project for which traffic or parking impacts are expressly mitigated by an ordinance adopted by the city, town, or county. 

State Environmental Policy Act—Categorical Exemptions.
Under SEPA, certain nonproject actions are categorically exempted from the requirements of SEPA.  Examples of categorically exempt nonproject actions include certain amendments to development regulations and certain amendments to technical codes.  The Department of Ecology is directed to adopt rules that establish additional classes of governmental actions that are categorically exempt from review under SEPA.

State Environmental Policy Act—Exemption from Review and Appeal. 
The adoption of ordinances, amendments to development regulations, and other nonproject actions taken by a city to implement certain actions related to increasing housing supply or to implement strategies adopted within a housing action plan, are not subject to environmental or judicial review or administrative or judicial appeal under the State Environmental Policy Act (SEPA).  

The adoption of development regulations or amendments by a city planning fully under the Growth Management Act (GMA) that increase housing capacity, increase housing affordability, and mitigate displacement and that apply outside of critical areas are not subject to environmental or judicial review under SEPA. 

Growth Management Act—Exemption from Review and Appeal.  
Any action taken by a city to amend its comprehensive plan, or to adopt or amend ordinances or development regulations, solely to implement certain actions related to increasing housing supply or to implement strategies adopted within a housing action plan is not subject to review or legal challenge under the GMA.

The adoption of development regulations or amendments by a city planning fully under the GMA that increase housing capacity, increase housing affordability, and mitigate displacement and that apply outside of critical areas are not subject to environmental or judicial review under the GMA. 

State Environmental Policy Act—Exemptions.
Project actions that pertain to residential, multifamily, or mixed-use development evaluated under SEPA by a city or town planning fully under the GMA are exempt from appeals under SEPA on the basis of the evaluation of or impacts to the aesthetics or light and glare elements of the environment, provided that the following requirements are met:

• the city or town evaluating the action is planning fully under the GMA; and
• the project must have been subject to design review pursuant to adopted design review requirements at the local government level.

"Design review", for the purposes of the exemptions described above, is defined as a formally adopted local government process by which projects are reviewed for compliance with design standards for the type of use adopted through local ordinance.

The existing exemption within SEPA that exists for certain project actions related to impacts to the transportation element of the environment is modified to provide that it does not apply if the Department of Transportation has found that the project will present significant adverse impacts to the state-owned transportation system.

By December 31, 2022, the Department of Ecology is required to modify its categorical exemption rules to accomplish the following: 

• add the construction of four attached single-family residential units to the current exemption that applies to the construction of four detached single family residential units; 
• create a new categorical exemption for single-family residential project types with a total square footage of fewer than 1,500 square feet in incorporated urban growth areas (UGAs) of at least 100 units; and
• increase the existing maximum categorical exemption levels for multifamily residential project types in incorporated UGAs from 60 units to 200 units.

Any applicant whose project qualifies as exempt or categorically exempt under SEPA is not required to file a checklist or any other paperwork to prove the exemption if the initial project application contains sufficient information showing that the project is exempt or categorically exempt under SEPA.