On Abundant Housing Michigan’s recent coalition call, our friends at YIMBY Oakland County mentioned that they’re trying to get Royal Oak to legalize the by-right construction of accessory dwelling units (ADUs). There is a petition, which you can sign here! ADU’s come up frequently, but there’s always this nagging question: if you legalize it, will they build? And if they build, will they build enough? In other words, how big a move is this?
Why By-Right
Core to the housing abundance movement– perhaps a corollary of the YIMBY movement- is the idea that people deserve to be able to build buildings on land they own. It’s not a radical idea until you realize that most of the country by land area is zoned as single-family, and the process of building anything but is an absolute nightmare, ranging from lengthy and expensive processes that involve construction or architectural documentation, serving of statutory notice, and even hosting public hearings, where every neighborhood resident can scream at you about how you’re going to turn their pristine residential neighborhood into the drug dens of Manhattan (?). Or, you know, whatever.
Accessory dwelling units– sometimes called mother-in-law suites or “granny flats”- are not, by any means, a new idea. But they’re gaining traction amid a nationwide housing crunch, a gradual rethinking of the nuclear family (especially as boomers realize that aging in exurbs, far away from younger family, can be challenging), and disruptions to long-held approaches to hospitality and short-term housing through platforms like AirBnB. Whether you’re looking at it as a glorified guest bedroom, a permanent home for mom, abuela, or whoever, or as an income-generating rental unit, it’s an affordable alternative to building a new house altogether.
An ADU is also easier to build than a whole house because it can be built on a simple slab or crawlspace as (usually) a one-story building. A garage with an apartment upstairs is another option. Because you already have site utilities, it’s easier to connect to them rather than to build from scratch.
But How To Get It Built?
The problem is that it’s not allowed in many jurisdictions. Most of the time, you’d have to appeal to a zoning authority for either a variance that would allow the special use, or a rezoning altogether to allow a higher density, depending on the jurisdiction. So, which jurisidictions have made it work?
California was doing piddly numbers on ADUs into the mid-2010s. The state theoretically kinda sorta permitted ADU development beginning in the 1980s, but a state law in 2017– amid a historic housing crunch that saw prices soar to hitherto unfathomable heights- revamped the process, preëmpting restrictive local red tape. And the boom commenced– with a 15,000% increase in ADU construction.
Is that fixing the state’s housing crisis? Not singlehandedly. But the ability to double the effective maximum residential densities by-right could definitely be hugely beneficial, especially in markets where housing is selling for upwards of $1,000 a foot and there simply is an inadequate flow of multifamily deals to make a dent in that.
ADUs are often more expensive to build per square foot, especially in markets with high construction and regulatory costs. But it’s instructive for thinking about how to affordably add units of housing, even if the high cost of construction might raise eyebrows. In other words? A house is a house, regardless of whether it’s a 300 square foot house or a 1500 square foot house.
Because an ADU will be suitable for some people and not others, it’s great to have options.
Similar Success Stories?
We’ve seen examples from bigger cities and smaller ones as well. Portland, Oregon, known for tight street grids with a high percentage of single-family housing, has done a great job of encouraging ADU development. Bend, Oregon, for example— around the same size as Ann Arbor- has its own an ADU program that seems to indicate that this works in smaller markets as well as bigger ones. Some states have enabling legislation but more are discussing it. The great thing about this is that ADU enabling legislation can be assembled much more easily and with far less political capital (or, should we say, eliciting far less rancor) than, say, a blanket preëmption on single-family zoning.
Stay tuned! And sign the petition!
Nat is on the board of Abundant Housing Michigan. Follow along with our adventures as we work to lobby for regulatory reform that will build better cities and better housing markets by reducing red tape and increasing housing supply!