Backyard cottages, mother-in-law suites and basement apartments are overlooked tools for addressing our city’s affordable-housing shortage. These small homes, collectively termed accessory dwelling units (ADUs), typically rent below market rate, and one in  10 provides free housing, usually to friends or family of the primary homeowner.

On top of this, ADUs can offer flexible living spaces for people in need of supportive housing who want to maintain their independence but remain near community. Rental income from these small homes can also help stabilize homeownership for some of our city’s lowest-income residents. Unfortunately, many of Seattle’s ADU regulations make these housing solutions all but impossible.

In June, the Seattle city council will vote to eliminate some of the biggest barriers to ADU construction. We urge them to adopt these long-overdue updates, increasing housing choices to meet our city’s diverse residents’ needs.

Let new council decide Seattle neighborhoods’ fate

Today, the city’s ADU owner occupancy requirement prohibits Parkview Services from building 15 backyard cottages to house extremely-low-income people with intellectual and developmental disabilities. As a nonprofit housing provider, we own and manage our homes, but we don’t live on-site. This means that we can’t build ADUs in the backyards of our existing properties.

In Seattle’s market, acquiring new property is so expensive that Parkview hasn’t been able to raise funds sufficient to develop a rental home in the city since 2004. If Seattle lifted the owner occupancy regulation, we could develop ADUs on each of our 15 Seattle properties and house an additional 20 people without purchasing new lots. These cottages would provide housing for extremely-low-income residents with disabilities in their community at rents they can afford.

Secondary suites also can provide much needed income for low- and moderate-income homeowners, particularly our city’s growing senior population. Rising property taxes and other home expenses are forcing many seniors on fixed incomes out of Seattle. They want to age in the home and communities they know and love but can’t afford to. Instead, they are forced to sell and move to less expensive cities like Kent and Tukwila.


Rental income from a backyard cottage or mother-in-law apartment could help provide the income necessary for them to stay in their homes. Nonprofit housing builders could help our seniors finance, manage and maintain these units. Unfortunately, Seattle’s ADU laws are working against us, driving up construction cost, or all together prohibiting construction on many lots.

Off-street parking requirements are one example: an extra parking space can add thousands of dollars to project cost. Current lot size requirements mean homeowners with smaller-than-average lots need not apply. These regulations put this housing solution out of reach for many Seattle homeowners looking for a way to hang on.

Seattle’s housing shortage hits low-income people hardest. Backyard cottages and mother-in-law suites can meet unique housing needs, providing independence, privacy and stability to some of our city’s most vulnerable residents. Removing barriers to this flexible housing type can give affordable housing developers the chance to give this new housing solution a try.