Updating Urban Residential Development Regulations


On October 18, 2017, the Snohomish County Council approved an ordinance (Ordinance No. 17-062 (PDF)) that modifies urban residential development regulations as outlined below. The ordinance became effective on December 17, 2017.


The County has adopted changes to urban residential development regulations. The code development project is an outgrowth of extensive internal and external stakeholder feedback on issues related to urban residential development. Through the outreach process, a variety of recurring themes were identified, such as:

  • Providing flexibility in orienting single-family attached residences toward common open spaces;
  • Reducing vehicular conflicts in townhouse developments resulting from short driveways;
  • Refreshing and recalibrating compatibility and design requirements;
  • Adjusting the approach to determining average final grade as it relates to building height for attached single-family housing;
  • Revising setback requirements from public roads;
  • Addressing challenges with making single-family attached projects financially and technically feasible; and
  • Allowing fee simple lot creation of developments with both townhouse units and a limited number of other single-family housing types.

Project Scope

The project scope for updating urban residential development regulations consists of five primary policy areas to:

  • Reduce barriers, incentivize, and enhance the quality of townhouse development;
  • Provide additional flexibility in the design of urban residential developments;
  • Recognize a new residential development type (“mixed townhouse”);
  • Expand unit lot subdivision provisions to permit the creation of fee simple lots for mixed townhouse developments; and
  • Modify the approach to determining average final grade as it relates to building height to recognize differences between detached and attached single-family residential development.
Neighborhood on slope with parked cars out front

What Is A Townhouse? And What Is Townhouse Development?

A townhouse is a form of single-family residential housing. Townhouses consist of three or more attached single-family dwelling units in the same structure. Each townhouse dwelling unit shares at least one wall with an another dwelling unit, and each dwelling unit is constructed to provide space vertically from the foundation to roof for individual occupancy by a household. The scale of townhouse structures is generally characterized by a low profile similar to that of other detached single-family residential homes, and the average dwelling size tends to be smaller. The width of townhouse structures, however, is typically longer because multiple dwelling units are attached in the same structure.

Townhouse development can provide an affordable alternative to larger single-family homes and suit the needs of many different household types. They're especially adept at serving smaller families and single individuals.

Townhomes in line

County defines townhouse dwellings in this way:

"Dwelling, Townhouse" ("Townhouse") means a single-family dwelling unit constructed in a group of three or more attached units in which each unit extends from the foundation to roof and has open space on at least two sides. The term includes a townhouse constructed as a zero lot line development and townhouse on single lot.

How Are Townhouse Developments Regulated?

The County's development code controls where and how townhouse developments may be created. The following are some of the key regulatory requirements for townhouse development:

Aerial view of naighborhood
  • Minimum setbacks from adjacent residential properties generally range from 5 feet to 25 feet, depending on proposed building heights and the zoning of an adjacent site and proposed development site. In certain circumstances, the required minimum setbacks may be greater.
  • Townhouse developments are subject specific urban design and livability requirements. Some of these requirements control site layout, internal and road networks, pedestrian circulation, architectural design, building orientation, on-site open space, and tree canopy and landscaping.
  • A minimum of two parking stalls is required per townhouse dwelling unit, except in the UC zone where a minimum of one parking stall per dwelling unit is required.
  • Townhouse developments may be subdivided through various provisions of County code. Typically, these developments are subdivided through the unit lot subdivision provisions (SCC 30.41A.205 and SCC 30.41B.205) allowing the creation of individual lots for each townhouse dwelling.
  • Townhouses can be developed with other housing types (single-family residential attached or detached, duplexes, and/or multi-family residential) or incorporated into a mixed-use development, depending on the underlying zoning allowances and applicable development regulations.

Project Contact

Stephen Fesler, Senior Planner
Email Stephen Fesler

Project Schedule

  • Fall 2016: Initial Stakeholder Outreach
  • Winter 2016: Draft Code Language
  • Spring 2017: Additional Stakeholder Outreach
  • May 2017: Planning Commission Briefing on May 23
  • June 2017: Planning Commission Hearing on June 27
  • October 2017: County Council Legislative Action

Project Documents