SEATTLE – Seattle City Councilmember Mike O’Brien released his proposal Thursday aimed at making it easier for Seattle homeowners to build mother-in-law units and backyard cottages.

The council passed legislation seven years ago that allowed people to build those types of structures in single-family zones throughout the city, but fewer than 200 have been constructed.

“I believe this is going to be a way to significantly increase the amount of housing supply that’s relatively non-disruptive,” O’Brien said.

At a time when city leaders are looking for ways to increase affordable housing stock, O’Brien’s hope is that – if 10 percent of qualified houses choose to add units – there would be 8,000 to 10,000 new units of added housing.

“We’re essentially going to remove some barriers to allow our community members, our homeowners, our residents to use their innovation and creativity to create some new opportunities for people to live,” O’Brien said.

In September 2014, councilmembers asked the Department of Planning and Development to explore policy changes that could increase the production of attached and detached accessory dwelling units.

The DPD report estimates there are almost 75,000 single-family zoned lots eligible for cottages. Changes to lot restrictions could take that above 80,000.

Mother-in-law units and backyard cottages were commonplace in Seattle until the 1950s. Over time, however, this type of housing fell out of favor and eventually was no longer permitted in Single Family zones until pilot programs started half a century later.

O’Brien's plan focuses on nine changes. The first changes the restricted size of the units from 800 square feet to 1,000 and current garage space would not count against that.

Janice Reebs, who’s lived in her Seattle home for about 25 years, recently added a backyard cottage as an art studio over her husband’s existing shop in the garage. She learned all of her hopes to comfortably house visiting family wouldn’t be realized.

“We really wanted a sleeping loft, you see. But we didn’t get to build it because we ran out of square footage. You’re only allowed 800 and the existing garage took up 450 or so of it,” she said. “If we could’ve had two feet higher, we could’ve had a really nice loft and we wouldn’t have had to cut down the garage if we didn’t want to.”

The new changes could allow one to two feet higher depending on the size of the lot. Also, currently, a lot must be 4,000 square feet to build these structures. Changes would take that down to 3,200.

The DPD report explored several alternatives that could increase the stock of these types of units. One of them was removing the owner-occupancy requirement. The rules on the books now require that a homeowner with an accessory dwelling unit either lives in the house or the accessory unit for at least six months a year. The new proposal would require the owner live on the property for one year.

“What this allows them to do is to be committed to the neighborhood but also have that flexibility,” O’Brien said.
The city also requires units to have off-street parking in most cases and is exploring removing that rule.

“Even if the rate of production increased tenfold, 500 DADUs (detached accessory dwelling units ) per year dispersed throughout the city would be unlikely to create a noticeable impact,” the report reads. “Some property owners that construct a DADU might elect to provide an off-street parking space even if not required.
Furthermore, some households that live in an ADU or DADU may not own a vehicle. Ongoing monitoring of DADU construction would allow the city to revisit these regulations if eventual production of ADUs and DADUs results in significant parking impacts."

“The interesting thing about this parking requirement is that often times the properties do not currently have a driveway and so to make an off-street parking spot they have to put in a curb cut to access the driveway, thus eliminating an on-street parking spot that everyone can use for their own off-street parking spot,” O’Brien said. “That doesn’t solve anyone’s problem. It just adds cost.”

The changes will go through the city’s legislative process this summer, including public comment.