Accessory Dwelling Units EIS

Final EIS Ruled Adequate

In October 2018, the City issued a Final Environmental Impact Statement (EIS). An appeal of the adequacy of the Final EIS was filed with the City’s Hearing Examiner. The hearing for this appeal concluded on March 29, 2019. On May 13, 2019, the Deputy Hearing Examiner ruled that our environmental review of the proposal to amend the Land Use Code to encourage ADUs adequately explores the potential environmental impacts of the proposal, clearing the way for the City Council to act on legislation.

Councilmember O’Brien will continue discussions of the proposal in the Sustainability & Transportation Committee on May 29, June 11, and June 18, 2019.  The June 11th meeting is an evening public hearing on the proposal.

The City proposes to remove regulatory barriers in the Land Use Code to make it easier for property owners to create accessory dwelling units (ADUs) and increase the number and variety of housing choices in Seattle’s single-family zones. Based on a decision from the City’s Hearing Examiner in December 2016, we have prepared an Environmental Impact Statement (EIS) that analyzes how the proposed Land Use Code changes could affect the environment.

Read the Final EIS or our one-page summary.

Draft EIS
Scoping
Background

Next Steps

On May 13, 2019, the Deputy Hearing Examiner ruled that our environmental review of the proposal to a encourage ADUs adequately explores the potential environmental impacts of the proposal, clearing the way for the City Council to act on legislation. The ADU proposal will be discussed at the following upcoming meetings of the Sustainability & Transportation Committee. All meetings will be held in the City Council Chambers, 2nd floor, Seattle City Hall, 600 Fourth Avenue.

Wednesday, May 29 at 2:00pm Briefing and discussion on proposed ADU legislation
Tuesday, June 11 at 5:30 p.m. Public Hearing on the proposed legislation
Tuesday, June 18 at 2:00 p.m. Discussion and possible vote on amendments and proposed legislation

For those unable to attend the public hearing, written comments may be sent to:

Councilmember Mike O’Brien
600 Fourth Avenue, Floor 2, PO Box 34025
Seattle, WA 98124-4025
or by email to Mike.OBrien@seattle.gov

Questions? Contact Aly Pennucci of the City Council Central Staff at (206) 684-8148 or via email at aly.pennucci@seattle.gov.

What is an ADU?

ADUs are small secondary dwelling units inside, attached to, or in the rear yard of a single- family house. An attached ADU (AADU), often called an in-law unit or basement apartment, is contained within or attached to a single- family house. A detached ADU (DADU), often called a backyard cottage, is a separate structure allowed in the rear yard of certain single-family-zoned lots. DADUs can be new structures or created through conversion of an existing structure, like a garage.

Published on October 4, 2018, our Final EIS includes a Preferred Alternative for Land Use Code changes to remove barriers to the creation of ADUs. The Preferred Alternative resembles legislation that the City Council will review and consider for adoption. Its key features include:

  • Allowing two ADUs on one lot
  • Removing the off-street parking requirement
  • Removing the owner-occupancy requirement and requiring one year of ownership when creating a second ADU
  • Modifying development standards that regulate the size, height, and location of DADUs
  • Increasing the household size limit for a lot with two ADUs
  • Establishing a new limit on the maximum size of single-family dwellings

The Final EIS identifies and describes potential environmental impacts that could result from removing regulatory barriers to ADU production. For more on the environmental review process, watch our What is an EIS? video and read about the State Environmental Policy Act at the Washington State Department of Ecology website.

ADU Final EIS

ADU Final EIS Appendices

Download by Section

Appendices

  1. Analysis of Housing and Socioeconomics impacts
  2. Parking Analysis Methods and Assumptions
  3. Aesthetics Modeling Methods and Assumptions
  4. Draft EIS Comments Submitted via Email
  5. Draft EIS Comments Received at the Public Hearing

Timeline

Issue Determination of Significance and Scoping Notice
Determination of Significance and Scoping Notice for the ADU EIS was issued on
October 2, 2017
Conduct SEPA Scoping
The scoping comment period will close at 5:00 p.m. on
November 1, 2017
Extended to November 16, 2017
Prepare Draft EIS
Scoping comments will be reviewed and the Draft EIS will be prepared
Issue Draft EIS
The Draft EIS was issued on May 10, 2018
Draft EIS Public Comment Period
The Draft EIS comment period closed on June 25, 2018.
The DEIS Public Hearing and Open House was on Thursday, May 31, 2018
Hearing location: Seattle City Hall, 600 4th Ave, Bertha Knight Landes room.
Hearing Handout Display Boards Watch Public Comment
Prepare Final EIS
The Final EIS addresses comments received during the comment period
Issue Final EIS
The Final EIS was issued on October 4, 2018
City Action
On May 13, 2019, the Deputy Hearing Examiner ruled that our environmental review of the proposal to a encourage ADUs adequately explores the potential environmental impacts of the proposal, clearing the way for the City Council to act on legislation. The ADU proposal will be discussed at the following upcoming meetings of the Sustainability & Transportation Committee. All meetings will be held in the City Council Chambers, 2nd floor, Seattle City Hall, 600 Fourth Avenue.

Study Area

Map of the ADU EIS study area