My family lives in a house in our friends’ backyard + What ADUs can (and can’t) fix in our city

I live in my friends' backyard along with my spouse Kelli and 16-month-old daughter. We all worked together (well, the baby didn't really help) to build a new house where a carport and patchy weed-filled yard was previously. And in the end it cost about as much or maybe a bit less than buying a lower-end condo of comparable size, though it could have been a bit cheaper had the city's very strange building codes been improved.

And that's exactly what the Seattle City Council unanimously did today. Congratulations to everyone who worked for years to get this passed (Full disclosure: My spouse Kelli is a legislative aid to ordinance sponsor Mike O'Brien).

After going through this whole years-long process to design, permit, finance and build our backyard house under the existing rules, I have some insight into what it takes to make projects like this happen. It was more difficult, took longer and cost more than I had originally expected. But much of that work was fun, and I am so happy with how it all turned out. And with these new rules making many of the steps easier, there are a lot of people who will find building backyard houses useful for many different reasons, such as:

• People partnering to share a property that they could not afford on their own. As a bonus, you get to be neighbors!
• People looking to generate extra monthly income.
• People hoping to age in their own neighborhood by downsizing into new smaller houses in their backyards and renting the main house.

In-fill housing like backyard cottages and basement apartments are an especially great way to increase the number of people who can live in our city's bikeable, walkable and transit-connected neighborhoods. Though this blog is focused mostly on transportation, that issue in intimately connected to land use. The way we build our communities determines how far people need to travel to meet their needs. Biking is one big way to cut costs, but that only works if your home is within biking distance of your needs. A lot of houses in so-called "single family" neighborhoods are a bit far from necessities by foot, but a very easy distance by bike. Biking and backyard houses go together perfectly.

But I also think it's important to understand the inherent challenges to building homes this way.

If you are partnering on such a project, you will find that financing can be very tricky. Mortgage lenders do not like non-standard arrangements or small-scale co-ops (our initial idea). You'll also need a pretty special group with the willingness to break that ancient rule: Never do business with friends. And, of course, this is not exactly a system that can scale well since every group will likely need to create an arrangement that works best for their unique situations and needs.

If someone already owns the property, they need to be willing to dedicate some of their space to build an ADU. While it's great that those who want to make this trade-off now have that option, I'm guessing only a small percentage of homeowners will choose to do so.

A city study estimates that under the new rules people will build 2,400 more backyard cottages in the next ten years for a total of 4,400 extra ADUs.

It's also important to point out that this rule change alone is not a replacement for subsidized housing programs or rent stabilization policies to help lower-income folks obtain or stay housed. Basement apartments are often on the cheaper end of market-rate housing options in a neighborhood, and these rules will make it easier to create those. That is a great and possibly under-celebrated element of these changes. Many people have underutilized basements just sitting there collecting spiders and holiday decorations. That could be someone's home (and in my experience living in such a basement apartment, the spiders will not be displaced).

But I doubt new backyard stand-alone houses are going to be low-end. They will certainly cost a fraction of what it would take to buy a whole house in the same neighborhood. But even if you were to make lower-cost decisions all along the way, the baseline cost of building a new house is significant. This is especially true when contractors (and sub-contractors) are in such high demand as they are around here these days. Simply finding a contractor who would consider a project of this size was a serious challenge.

A backyard house is one more home, which takes one more potential bidder or applicant out of the market for other homes in the city. Anyone bidding on low-end Capitol Hill co-op units won't have to compete with us now, for example. But though that's certainly part of the solution, "trickle-down" housing policy on its own is not going to make the city affordable for lower-income people and families or help people struggling today. We still need to make major public investments in subsidized housing, and we still need to better protect people who are struggling to keep up with their rising housing costs.

I love this ADU legislation, but don't for a second think that this work is over.

Ultimately, these rule changes should not have been this difficult or this big of a deal. It's one small relief valve for the city's housing supply problem, but it's not a complete solution. It's the kind of thing the City Council should have simply passed in the normal course of city business years ago before moving on to other work. Part of me worries that the amount of effort and debate we've put into this has inflated its potential a bit. That's perhaps the real impact of all those lawsuits. It wasn't about stopping these rules in particular, it was about derailing progress on more significant rule changes like legalizing apartments in residential neighborhoods or allowing smaller lot divisions.