Planning for Middle Housing

For those communities seeking a time extension or the use of the substantially similar alternative for compliance, please utilize the following. The guidance in the fact sheets is interim, until such time the Washington Administrative Code (WAC) update addressing housing bills is adopted in early 2025. The adopted WAC will identify the final alternative pathway review and application processes.

• Time extension to address displacement fact sheet (PDF)
• Time extension due to lack of infrastructure capacity fact sheet (PDF)
• Substantially similar alternative (PDF)

Jurisdictions making an application to Commerce for a time extension certification or substantially similar approval referenced above must complete and submit the following application form and applicable checklist with their application. The check boxes in the application submittal checklists are to be used to confirm that all required information is provided with the application.

• Application form (Word)
• Application checklist – Time extension to address displacement (Word)
• Application checklist – Time extension to address infrastructure capacity (Word)
• Application checklist – Substantially similar alternative (Word)

The provisions of RCW 36.70A.622 apply to jurisdictions’ off-street parking requirements for any type of residential development or redevelopment, regardless of the nature of the use. This includes, but is not limited to, detached single-family residences, accessory dwelling units, middle housing, multifamily housing, co-living housing, senior housing, assisted living facilities and nursing homes and group homes. The following Fact Sheet is intended to be a support to a jurisdiction review and adoption of the state statute.

• Residential Parking fact sheet (PDF)
• Residential Parking checklist (Word)

For cities and counties planning under the Growth Management Act, these regulations are required to be adopted by their next periodic update for comprehensive plans and development regulations. See WAC 365-196-610 or Commerce’s periodic update page for information on specific deadlines.

Empirical parking study guidance

Both Middle Housing and Accessory Dwelling Unit requirements include options for developing an empirical parking study to determine appropriate parking requirements (outside of the requirements of state statute). The following documents provide guidance to local governments in developing an Empirical Parking Study and in making a certification request to Commerce.

• Empirical parking study guidance (PDF)
• Empirical parking study application checklist (PDF) 
• Empirical parking study presentation slides (PPT)
• Empirical parking study presentation video recording (Vimeo)

This co-living guidance is intended to support planners, advisory bodies, elected officials and interested parties in implementing code amendments related to RCW 36.70A.535. This guidance uses diagrams, references to public informational documents, and real-world examples to offer recommendations and best practices for the development of co-living housing.

• Co-living guidance (PDF)
• Co-living model ordinance (Word)
• Co-living parking study guidance (PDF)
• Co-living parking study factsheet (PDF)
• Co-living parking evaluation checklist (PDF)

In 2023, Washington state law changed to require unit lot subdivisions be included in short plat regulations for all cities, towns, and counties to be adopted before or with their next periodic update of comprehensive plans and development regulations. See RCW 36.70A.130 and Commerce’s periodic update page for more information on deadlines.

A unit lot subdivision (ULS) creates new lots much like a typical subdivision, except a ULS allows flexible application of dimensional standards. In a ULS, the development as a whole is on the “parent lot” which conforms to the zoning dimensional standards while individual “unit lots” are not required to. Unit lots (also called child lots) are individual, sellable, legal lots of record with their own tax or parcel identification number.

• Unit Lot Subdivision fact sheet (PDF)

These fact sheets provide a high-level summary related to proportional residential changes to impact fees and system development charges. Detailed guidance for calculating proportional fees is expected to be issued in the Spring of 2025.

• Impact Fees fact sheet (PDF)
• System Development Charges fact sheet (PDF)

Neighborhood infill development guidance addresses potential barriers to the development of neighborhood infill housing, provides examples of proactive solutions, and provides resources for planners to lead discussions with service providers.

• Neighborhood Infill Guidance – Related Disciplines (PDF)
  
  The Neighborhood Commercial Fact Sheet was developed at the request of cities, to encourage commercial opportunities compatible with neighborhoods. Permitting neighborhood commercial goes hand-in-hand with increased allowances for residential density. Additionally, it can help facilitate infrastructure improvements.
  
• Neighborhood Commercial Fact Sheet (PDF)

Manufactured/mobile home communities (MHCs) are residential areas that house multiple manufactured or mobile homes with shared infrastructure and amenities.

As communities across the state plan for housing that meets the needs of all income segments, they should take a careful look at this naturally occurring source of affordable housing.

Commerce has prepared the following guide to help local governments consider preserving this housing type.

• Manufactured/Mobile Home Community Preservation for Local Governments

• General Middle Housing FAQ (PDF)
• Jurisdictions subject to Chapter 332, Laws of 2023 (PDF)
• Middle Housing Building Types (PDF)
• Middle Housing Lot and Block Models (PDF)
• Middle Housing – Introduction (PPT)
• Middle Housing Study (PPT)
• Middle Housing – What, How and Where? (PPT)
• Middle Housing – How Do We Get More? (PPT)
• Middle Housing Summary of Resources (PPT)
• Middle Housing Presentation Videos
• Middle Housing appraiser engagement FAQ (PDF)

• Middle Housing Pro forma: Puget Sound Region Final (Excel)
• Middle Housing Pro Forma: Feasibility Attainability Slides (PDF)
• Middle Housing Pro Forma: Presentation Recording
• Appendix A: Middle Housing Market Assessment (PDF)
• Appendix B: Pro Forma Calibration and Assumptions (PDF)
• Appendix C: Middle Housing Pro Forma User Guide (PDF)
• Appendix D: Middle Housing Sensitivity Testing (PDF)

• Middle Housing Placetype Atlas (PDF)
• Middle Housing User Guide (PDF)
• Middle Housing Objective Design  Standard Basic Toolkit (PDF)
• Middle Housing Objective Design Standard Detailed Toolkit (PDF)