Let Us Build Backyard Cottages


A few weeks ago, former Seattle Councilmember Tom Rasmussen wrote an opinion piece for The Seattle Times, which theorized that loosening Seattle’s backyard cottage rules might allow developers to exploit loopholes to build multi-family housing in areas zoned for single-family homes.

Instead of focusing on what developers might do, we should focus on how the current backyard cottage rules keep homeowners, like me, from building backyard cottages.

Example of a DADU. (City of Seattle)
Example of a DADU. (City of Seattle)

Backyard cottages (also known as mother-in-law cottages, detached accessory dwelling units, or DADUs) are a great way to increase density in a neighborhood without tearing down existing housing stock or altering the character of a neighborhood. Because they’re located in a backyard, they’re often not even visible from the street. They’re naturally small, as they must fit within the footprint of an existing lot with a house on it. Seattle additionally limits their size to no more than 800 square feet. As Seattle seeks to increase its absolute housing stock to combat rising rents, backyard cottages provide a comfortable and low-cost option for individuals and small families.

I bought my home in 2014 with the intent of building a backyard cottage on the property. The property is a mere 4,080 square feet, with a large flat backyard that is mostly wasted space. The plan was to buy a small, prefabricated, and super-insulated (to Passive House standards) house. We would install it and move into it while we brought the main house up to Passive House standards as well, adding insulation and ventilation. We would then move into the main house while my parents (who are currently living on the East Coast, and want to move closer to us) move into the backyard cottage.

Anyone who thinks kids need a backyard should meet mine, who never spend time here.
Anyone who thinks kids need a backyard should meet mine, who never spend time here.

Unfortunately, Seattle’s backyard cottage requirements proved too onerous for us to move forward with building one. The requirement of an additional parking space was a bit irritating (especially considering that my family lives car-free near the future Roosevelt light rail station), despite the fact that we do technically have two parking spaces. But more frustrating than that, it was the owner-occupancy requirement that made us scrap our backyard cottage plans.

The owner-occupancy rule requires that we sign a covenant with the City promising that we would spend at least half the year living on the property. In the case that either my wife or I wanted to spend more than six months out of state in any year, we’d need to ask the City for permission. If we didn’t get permission, we’d either need to stay put, rip out the pieces that make it a separate cottage (including plumbing and electrical fixtures), or risk excessive fines. We could easily imagine situations where a family member with health problems meant we’d need to live outside of Seattle for half of the year.

This rule turns a backyard cottage from a feature into a liability. It applies to anyone we might sell the property to. This lowers our property values, as the property is less appealing to someone who would need to either sign the covenant or rip out the cottage after they acquire the property. It also lowers the number of prospective buyers, which could be truly problematic in a down market. I know it’s hard to imagine a slowdown in Seattle’s red-hot housing market right now, but they do happen!

The rule also stifles any sort of local backyard cottage building industry. Shipping a house long distances is expensive. We found plenty of prefab house suppliers in other cities, but Seattle only had a few local prefab makers. Those local prefab house suppliers all had buildings bigger than 800 square feet with the exception of one (who wouldn’t return our emails or calls). After reading more about the owner-occupancy rule, we understood why.

The upside of limiting housing with insane rules like the owner-occupancy requirement. (Zillow)
The upside of limiting housing with insane rules like the owner-occupancy requirement. (Zillow)

Instead of moving into a backyard cottage, my parents will likely need to buy a separate house or condo. This will further diminish Seattle’s available housing stock, increasing rents and housing prices. If Seattle wants homeowners to build backyard cottages, it should examine why people are not currently doing so instead of worrying about developers exploiting theoretical loopholes.

The Office of Planning and Community Development will hold a public meeting tonight (Wednesday, February 3rd) to discuss backyard cottage regulatory changes. It will be held at the Wallingford Community Senior Center from 6pm to 7.30pm. Weigh in on the issues with City staff, including Councilmember Mike O’Brien. 

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Andres Salomon is a dad, safe streets advocate, and former mayoral candidate. He lives in Northeast Seattle.

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Nicholas Crosser

What a great post. I am in this very predicament only I have finished the backyard cottage and worry about what would happen if I need to sell or move. I would really want to keep my home and come back but cannot under the rules. I really don’t get how an individual can have unlimited rentals in Seattle and live elsewhere but god forbid you have one backyard cottage and all of a sudden you must live at that property full time. Really, I am not sure how the city can legally make the restricition. the number of given folks on the property never changes whether it is a rental or not.


Lot coverage and existing rules on utilities, etc. should be the only limitations. No minimum square footage, no owner-occupied requirements. Just “You can’t cover more than X% with buildings, you can’t shed more than X stormwater direct into the system, you can’t consume more than X electricity, water, etc. per lot. I’d be good with all that.

But the weird rules around cottages are mostly just a FrankeNimby rule set meant to protect incumbents and keep things unchanged.

My lot is <50 square feet from the bottom limit. I can put a GARAGE that covers more of my lot than a cottage would right now, without a problem, and give it plumbing and electricity, and the whole 9. But a cottage? Nope.

That's silly.


I fully agree with making major changes to the code to allow more backyard cottage construction. The stated purpose of the cottages (and mother-in-law apartments inside the main house) is to provide options for homeowners: extra income to pay for increasing costs, or options for extended family members. So some type of owner-occupancy regulations seem appropriate, but we can probably make them flexible enough to accommodate situations like you describe.


Interested to hear how your family lives car free in NE — the practicalities, like where do you go over the course of a week and how do you get there (keeping privacy issues in mind). And, do you do this with kids? And, how would your accessory dweller live car free?

This is the piece of the story that I”ve found missing at the Urbanist site. I like being asked to think out of the box of my single family house/car suburban mindset, but want to know how it’s done in practical terms. I often feel like the world envisioned is one that includes only fit, young, singles and couples, without children and without constraints on time and physical needs.


Hi zbreeze,

In case you are interested, below are two pieces on folks living in Seattle without cars.



I know many, many people who live in the city without a car, including myself, and it’s definitely not just young fit folks without kids.


Thanks — those are lovely cites.

Andres Salomon

Sure. I have a kid in preschool near Green Lake, so we go there a lot. My wife likes to jog there with a jogging stroller when she does drop-off/pick-up, while I prefer to take a cargo bike. There’s no direct bus route, but happily there’s a bridge over I-5 (on NE 70th) that goes right there and isn’t a death trap (like NE 45th is). I’m working on a grant to get that bridge to, uh, suck less for people walking.

We go to UDistrict multiple times a week for meals, shopping, the farmer’s market, etc. We’ll walk, bike, or take the 72/73.

I used to go downtown for meetings, but in the past 6 months or so Metro service has become TERRIBLE. Lots of delays and no-shows (where OneBusAway claims a bus is arriving and then it has arrived, but it just never shows up). I don’t bike down there – I’ve had too many close calls, both in downtown proper and getting there. So I’m boycotting downtown until light rail opens up, at which point I’ll bike down to the UW station. 🙂

My wife works on the eastside. She works from home half of the week, and bikes to work anywhere from 1-3 days per week. She bikes down to I-90 and rides across the bridge. It’s a 1.5 hour commute (each way, so 3 hours total), but she likes the exercise.

We also walk or bike regularly to businesses in Roosevelt, Maple Leaf, and the Northgate/Licton Springs area.

When I need the occasional 8×4 insulation or OSB panel, I’ll just have a bunch delivered. Let’s be honest, even with a car I wouldn’t be strapping that on there. I have hauled a chicken coop home by cargo bike, which looked pretty ridiculous but actually wasn’t bad (bulky, but light). A friend offered to haul it in her car, but it wouldn’t fit.

We occasionally do trips outside of Seattle. For some reason, our friends keep deciding that Poulsbo is the place to get married, so the past few years we’ve done a few bike trips out there. It’s a nice ride, with the exception of one scary/sketchy bridge. The Interurban is a great way to get up north.

The cargo bike (which we both use) is what allows us to live car-free. In other places I’ve lived, I’ve been able to live car-free by just relying on public transit, but Seattle’s not there yet. At least not NE Seattle.

Andres Salomon

Oh, and my parents come from a car-centric area of the east coast. They’d probably bring a car with them, at least initially. It’s unclear how much they’d use it (they enjoy being able to walk to the store when they visit), but that’s something we’d have to consider after they settle in and set up a life here.


Nice review — thanks for the summary. I hate it when people say it can’t be done, but also when people say it can be done, but don’t tell you how they do it. Seeing the picture of how someone does something (living car free, living in less space, . . . .) let’s people decide for themselves how they could make it work for them, and whether they are willing to make the choices.


Sorry you couldn’t make it work, Andres


Prefab cottages are a challenge for three reasons: getting the prefabs to the site is not always feasible given the tight confines of many seattle neighborhoods, two, the height limits do not lend themselves to the way prefab boxes are built to stack (each box has a floor and ceiling, and no slab on grade possibility meaning redundant structure reducing the available head height on the second floor), and every yard is different (access, alley, solar orientation, mature vegetation, topography). All in all, it makes prefab a tough sell given the constraints.