Environmental Impact Study Builds the Case for Accessory Dwelling Units in Seattle

Proponents of a new Accessory Dwelling Unit rule in Seattle say the tactics of opponents backfired with this Environmental Impact Study.

2 minute read

May 24, 2018, 12:00 PM PDT

By James Brasuell @CasualBrasuell


Accessory Dwelling Unit

radcliffe dacanay / Flickr

Dan Bertolet reports from Seattle, where the city recently released a highly anticipated Environmental Impact Study (EIS) on a proposed rule change that would allow for more construction of Accessory Dwelling Units in Seattle's residential neighborhoods.

According to Bertolet, the study was provoked by an appeal by anti-development activists led by Marty Kaplan. Bertolet provides a scathing critique of Kaplan's obstructionist positions in an earlier post from April 2017.

Now the environmental study responds to the appeal, and Bertolet says it reveals the appeal as "bunk": "baseless claims eviscerated by analysis and evidence." As an example, see here Bertolet's analysis of concerns about displacement:

The appeal’s most grievous complaint was that making it easier to build accessory dwelling units (ADUs) would lead to displacement in lower-income communities of color. In other words, poor people would lose homes to rich speculators. 

The appeal’s most grievous complaint was that making it easier to build accessory dwelling units (ADUs) would lead to displacement in lower-income communities of color. In other words, poor people would lose homes to rich speculators. As the appeal’s de-facto leader, Marty Kaplan, warned: “There would be a feeding frenzy for anybody with a truck and a nail bag to go buy homes and convert them into three rental units and displace the population.”

Math begs to differ. The EIS finds that relaxing ADU rules would lead to fewer teardowns of existing single-family houses—which would decrease the likelihood of renter displacement—and that teardowns are less likely in lower-priced neighborhoods to begin with. It also demonstrates that in Seattle the value of selling a house, with or without ADUs, eclipses the value derived from renting. So much for any rental conversion “feeding frenzy.”

Bertolet also analyzes the study's findings regarding parking, before pointing a finger at the enabler for the study's delay: the Washington State Environmental Policy Act (SEPA). A lot more analysis of the study follows. If you're looking for more, there's also another article along the same lines written earlier in the week by Erica Barnett.

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