By Erica C. Barnett

On the local campaign trail this year, you can’t go to a debate without hearing multiple candidates profess their support for “Comp Plan Alternative 5″—the densest potential option currently on the table for the city’s comprehensive plan update, which will serve as a framework for Seattle’s future growth and development for the next 15 years.

It’s a kind of proxy for an urbanist (or urbanist-lite) position on development that fits neatly into a 30-second debate response: Supporting Alternative 5 signals that you support housing as dense as fourplexes (or even sixplexes!) in areas that were previously zoned exclusively for detached single-family houses—a marked departure from the bad old days when even backyard or basement apartments were a third rail for the homeowner activists who dominated the public debate over density.

We’ve expressed optimism in the past about the way the Overton Window has shifted on density and housing. This, at least, is undeniable: Polls show that Seattle residents are increasingly receptive to the idea of “more housing in my neighborhood,” and politicians have come along, including many on the left who have come to support density coupled with anti-gentrification measures, like targeted investments in affordable housing, homeownership, and preservation.

But lately, I’ve started to think that my optimism may have been misplaced. This is because while the concept of “more housing” is generally popular, the kind of housing people say they support is actually a very specific type: Modest density that looks like the rest of an existing neighborhood—the kind of inoffensive density you don’t even notice if you aren’t looking for it. Ask a moderate candidate what they mean when they talk about density in residential neighborhoods, and they’ll often describe a fourplex built about 80 years ago— the type that blends in to a single-family neighborhood because it looks an awful lot like the the single-family houses that surround it.

When pressed, candidates are often explicit about this preference. Take Maritza Rivera, running in District 4. When David Hyde, moderating a debate at Roosevelt High School, asked the candidates what they thought of a new state law that allows fourplexes in formerly exclusive single-family areas, Rivera said she supported increasing density “gradually” in a way that preserves “the character of the neighborhood…  for instance, on north Capitol Hill, you can see there are some places that look like mansions, but they’re actually fourplexes.” Or Maren Costa, in District 1, who talked about creating a set of pre-approved architectural plans that homeowners could use to convert their property into a fourplex while adhering to the current neighborhood vibe.

It’s thoroughly unrealistic (and, I would argue, a form of creeping architectural fascism) for a big city to dictate what housing in a neighborhood must look like. But the problem goes deeper than aesthetics, and gets to the question that has been nagging me for months: Are fourplexes real? That is: If we zone the whole city to allow fourplexes everywhere, will they get built? To drill down even further: Will developers find it possible–in other words, profitable— to build four-unit rental housing developments on single-family lots?

My belief, increasingly, is that fourplexes are not a viable option for replacing single-family houses in Seattle—but apartments are. Which is why it’s time for urbanists to stop conceding this point. We have to stop settling for “plexes”—and start advocating for apartments everywhere.

This doesn’t mean allowing high-rises in Laurelhurst, or eliminating tree protections (which, by the way, are easier to follow when housing can go up instead of sprawling out). But it does mean allowing regular old apartment buildings (not “sixplexes”; not “stacked flats”) in a lot more places, and allowing taller, denser apartment buildings everywhere short, stumpy apartment buildings are currently allowed.

I’m not a developer, and I don’t pretend to have the precise zoning formula for what will pencil out for builders and actually create housing in the city, rather than just on paper. (I mean: No zoning at all works pretty well in Houston, but I’m not a lunatic. I know where I live.) What I do know is that when other cities have tried to go for modest, tentative density, it hasn’t worked out the way they hoped.

Just look at Minneapolis, which, in 2019, made nationwide headlines as the first city to “eliminate single-family zoning” outright by allowing triplexes everywhere. The city was seen as a model for the kind of modest, infill density known as “missing middle” housing, including by hopeful urbanists in Seattle. The housing advocates at the Sightline Institute, for instance, argued that by allowing triplexes, cities could start to undo the “ugly legacy of economic and racial exclusion” and break “the entrenched stranglehold of exclusionary zoning.”

Fast forward to 2023, and just 17 triplexes have been built in areas previously zoned for single-family use in Minneapolis, a blow to the idea that cities can encourage “gentle” density by gingerly increasing what’s allowed in formerly redlined neighborhoods.

One reason triplexes didn’t catch on in Minneapolis is that formerly single-family areas retained their old envelope (height and lot coverage) limitations, which means that the new three-unit buildings can’t take up much more physical space than the houses they replace. If you allow developers to build more units but don’t let them build up or out, it turns out they decide to build housing that’s more profitable—like $950,000 townhouses, or 100-unit apartment buildings in the narrow slivers of the city, generally along multi-lane arterials, where renters are mostly allowed to live. You can argue that this is developer greed or unwillingness to get creative or rapacious gentrification all you want; what matters is that this kind of housing, though now legal in Minneapolis, isn’t getting built.

Seattle is facing a similar path. Although the city hasn’t released all the details of the five comprehensive plan options yet—an environmental impact statement that will include this information has been delayed from April to November of this year—a high-level “scoping” document says that new, market-rate “plexes” will have to fit within current height and zoning limits for single-family areas, which means Seattle will likely run into the same problem as Minneapolis.

The city’s Mandatory Housing Affordability Program, which allows developers to build more density in small portions of formerly exclusively detached, single family homes, in exchange for building affordable housing (or paying for it elsewhere) provides a local example of what happens when the city plans for a type of development without considering whether it’s practical for developers to build.

Townhouses, which were the city’s dominant low-density development type before MHA passed in 2019, have all but dried up, shrinking from more than 1,800 permits filed in 2018 to just 165 in the first nine months of 2023. This isn’t because people weren’t buying townhouses; it’s because developers can’t make them pencil out now that they have to either build one or two affordable townhouses per four- or six-house development or pay tens of thousands of dollars in MHA fees.

Paradoxically, if we do increase Seattle’s theoretical zoning capacity without actually increasing the amount of housing, urbanists could end up playing directly into NIMBY hands. For decades, traditional neighborhood activists have argued against upzoning by pointing out that there is already “plenty of zoning capacity” in Seattle to accommodate future growth; in other words, if every parcel of land in Seattle was built out to its maximum allowable density, there would be enough housing for everyone.

The problem with this faux density argument is that capacity isn’t housing until someone builds it. Until then, it’s existing housing that people already live in—from the  affordable dingbat apartment building that’s been hanging around since the 1960s to the Craftsman bungalow that could be, but hasn’t been, replaced by a triplex. This “capacity” argument has lost currency in the face of Seattle’s growing affordability crisis, as Seattle residents have generally come to accept that we probably could stand to add a bit more density. Adding more theoretical  capacity—even, perhaps especially, in the absence of actual housing—will only give NIMBYs another reason to argue that Seattle has plenty of room to grow.

I’m not completely giving up hope on the possibility that Seattle may yet build more rental housing, and even affordable housing, in its traditionally single-family areas. But I am going to start looking beyond “fourplexes” and “sixplexes” as that housing solution, because I don’t believe it’s going to happen—at least, not in a way that meaningfully makes a dent in the 112,000-unit shortfall we’re expected to face over the next 21 years. Instead of “plexes,” we need apartments—and that means building densely, not tentatively, everywhere in the city.

We could start by re-legalizing small, aPodment-style apartments and bringing back single-room occupancy units—housing types that may shock the sensibilities of people who think everyone needs two sinks in their 180-square-foot microunit but that will be popular among people who don’t have a lot of stuff, or those who would otherwise be unsheltered.

So let’s stop equivocating, or using euphemisms, to describe the changes we must make in order to have any hope of being the kind of city where working people can afford to live. We need apartments where people can live—not imaginary plexes that “fit in” to our existing suburban-style neighborhoods.