The Seattle City Council voted unanimously Monday to enable the construction of more and larger backyard cottages in all neighborhoods while removing requirements that property owners live on site and provide off-street parking.

Councilmember Mike O’Brien and other proponents touted the new rules for accessory units as a gentle and environmentally-sustainable way to add living options in response to the city’s population growth. They say it will open up pricey neighborhoods to people who can’t afford to buy or rent single-family houses.

Proponents included urbanists, labor unions and homebuilders. AARP has said accessory units can provide senior homeowners with extra income and other seniors with the means to live independently alongside their children.

“This is going to be an opportunity to invite so many more people into some of our most exclusive neighborhoods and make (those neighborhoods) stronger,” O’Brien said before an 8-0 vote, with Council President Bruce Harrell absent.

Critics of the new rules, led by the Queen Anne Community Council, warned about the changes allowing developers to replace modest older houses with up to three rental units.

The opponents said the plan would make Seattle’s low-density blocks less desirable and create parking problems without yielding truly affordable options. They said the changes could contribute to gentrification while reducing home-ownership opportunities.


The Queen Anne group blocked the legislation for more than two years with legal challenges, arguing the city’s environmental-impact analyses were inadequate.

“I think it’s a disaster,” longtime resident Johanna Surla said Monday during a public-comment session. “It won’t improve affordability for people at all.”

Mayor Jenny Durkan has supported the new rules while saying they should be tailored for homeowners, rather than developers. In a statement, she hailed the council’s vote as an “important step” and said more work must be done to streamline construction permitting. The rules are set to take effect 30 days after Durkan signs her approval.

Monday’s legislation will allow a backyard cottage and a parent-in-law apartment or two parent-in-law apartments on the same lot, rather than only one accessory unit per lot.

Backyard cottages are detached from a main house, while parent-in-law apartments are included, usually in the basement.

Property owners with accessory units will no longer be required to live on site and will no longer be required to provide off-street parking for accessory units.


Councilmember Lisa Herbold proposed that Seattle require a year of continuous ownership before allowing a second accessory unit to be built. Herbold said that would protect people now renting old, single-family houses from being displaced by speculators.

Real estate developer Sara Weaver had earlier told the crowd, “If you think that investors aren’t going to be coming in to pick up these properties, you’re sadly wrong.”

The council rejected Herbold’s amendment 7-1, with Councilmembers Teresa Mosqueda and Kshama Sawant pointing to other cities with relaxed rules. In Portland and elsewhere, longtime owners have built cottages and speculation hasn’t been a major problem, Mosqueda said, describing cottages as a way to help remedy racist historical zoning practices.

She and Sawant rejected the notion that renters are less responsible community members whose presence detracts from neighborhood blocks.

Under the new rules, backyard cottages will be allowed to have 1,000 square feet of floor area, up from 800 square feet. Parent-in-law apartments already are capped at 1,000 square feet. Taller cottages also will be allowed.

Meanwhile, backyard cottages will be allowed on smaller lots and up to 12 unrelated people will be allowed to live on a lot with two accessory units, up from eight unrelated people.


While loosening restrictions on accessory units, the new rules will tighten restrictions on the construction of single-family houses by outlawing certain large homes, based on their floor area and lot size.

The aboveground living space for a single family in a new house will be limited to half the square footage of the home’s lot. For example, a new house on a 6,000-square-foot lot will be limited to 3,000 square feet of aboveground living space, not counting space devoted to an accessory unit.

O’Brien has said the “McMansion” ban will discourage people from replacing modest older houses with more expensive new houses and will encourage them to add accessory units.

The city’s most recent environmental analysis estimated the new rules would result in 4,430 accessory units built and 1,580 houses torn down over 10 years, versus 1,970 accessory units built and 2,030 houses razed under the status quo.

The changes are too modest to dramatically remake neighborhoods, O’Brien said. Seattle added 7,400 housing units last year.

During the public-comment period, Wedgwood resident Per-Olaf Swanson expressed concern about removing the parking requirement for accessory units. “I would love Seattle to be a city where you didn’t need to drive, but that’s not the case,” he said.


Wallingford resident Jessica Westgren disagreed. “I’ve never owned a car in Seattle,” noted Westgren, who moved to the city in 2007.

Banned about 70 years ago in Seattle, parent-in-law apartments were again allowed across the city starting in 1994 and backyard cottages since 2010.

The cottages conversation has been part of a broader debate about housing options in Seattle and other costly areas. Minneapolis moved to allow triplexes on all residential lots last year, and Oregon lawmakers passed a bill Sunday to allow duplexes on residential lots in cities across the state.

Seattle earlier this year made changes to allow taller buildings and denser housing in 27 urban villages.