Sightline: The Zoned Capacity Myth in Seattle


From the Sightline Institute.  This will sound familiar in Vancouver too, where Elizabeth Murphy in The Sun argues that there is plenty of zoned capacity in this city.



[Residents] might also ask why the city insists on ever-taller buildings and doubling or tripling density in single-family zones with accessory dwelling units, even though planners say current zoning has plenty of capacity.

So declared the Seattle Times editorial board, parroting one of the most persistent and ubiquitous arguments made during zoning debates far and wide, a rallying cry in neighborhood preservation circles not only in Seattle but in cities across Cascadia and beyond. “We have plenty of zoned capacity” is repeated credulously and earnestly by citizen activists and homeowners at city council meetings and community forums and in online debates (see here, here, here, here, here, here, here, here, here, here).

The zoned capacity argument is also false. It’s a myth. That’s what anyone who carefully looks into the numbers on zoned capacity and the methodology for estimating them can’t help but conclude.

What makes the myth plausible, though, is that zoned capacity—how many new homes could theoretically be built under zoning rules—is a real data point that Seattle and other cities estimate and publish. (You can find it here for Seattle and here for Portland, for example.) And these estimates invariably indicate that there is plenty of zoned capacity to accommodate projected population growth, leading people to wrongly assume that their city is making enough room for newcomers. Reaching that conclusion may be an understandable layperson mistake. For knowledgeable advocates, however, it’s more like malpractice. …

But first, a more important point—in fact, the most important thing to know about zoned capacity: in every city, zoned capacity is a side show to the main event. The main event is housing prices.

sightline-4Housing prices are the crux of the matter. They reveal if people have enough housing choices. If vacancy rates are low and rents and housing prices are rising, then a city needs more homes. Period. The city needs to remove zoning-code barriers to more housing, so that builders can construct more homes. …

… here’s a summary of the key reasons Seattle’s zoned capacity estimate is misleading and does not justify halting upzones:

  • The assessment overestimates zoned capacity. It ignores many real-world obstacles to housing development.
  • Most of Seattle’s zoned capacity is in dense commercial areas, which are less family-friendly and more likely to expose residents to air pollution and automobile hazards.
  • Seattle’s zoned capacity is shrinking as construction booms. The best building sites are already gone, and others are going fast. The faster a city grows, the sooner it makes sense to upzone and keep plenty of buildable sites available.
  • Delaying upzones has the paradoxical effect of reducing future zoned capacity. Every building erected to four stories rather than eight, because zoning is too restrictive, represents four floors of potential homes denied to the city for as much as a century.
  • Seattle’s population is growing much faster than projected. …


The numbers are wrong: Why Seattle’s zoned capacity estimate is too high

1. It ignores how buildings actually get built

2. It ignores that Seattle is using up its “lowest hanging fruit” zoned capacity and neglecting future capacity needs.

3. It relies on a too-low population projection.

The values are wrong: Seattle’s zoned capacity does not promote equity

1. The capacity is not zoned as a shared responsibility across neighborhoods.

2. The capacity is not zoned as family-friendly or environmentally just.

… estimating zoned capacity is a theoretical exercise that ignores many of the factors that determine whether or not housing gets built: timeline, fluctuating costs and prices, unwilling sellers and the challenges of parcel assemblage, mismatches between zoning and demand, neighborhood opposition that delays or shrinks or scares away new housing, concentration of zoned capacity in dense districts with worse air and traffic and that are outside of the most desirable neighborhoods.

Zoned capacity also gets consumed by new construction itself, especially when zoning causes smaller buildings with fewer homes to be built, which locks in housing shortages in desired locations for decades. And lastly, in Seattle’s case, the “plenty of zoning capacity” myth implodes not only because the estimate itself is so flawed, but also because the city’s population is growing twice as fast as planners projected.

But as I noted at the outset, zoned capacity is a sideshow, a technical curiosity. Invoking zoned capacity as an argument against more homes for people in Seattle or any other growing city reveals nothing so much as the misunderstanding of those making the argument.

Full article here.

19 thoughts on “Sightline: The Zoned Capacity Myth in Seattle”

  1. Dan Ross said:

    Agreed. Anyone who uses the ‘but there’s enough zoning capacity’ claim is either being disingenuous or simply does not understand what zoning is and does (and does not do).

    It simply creates the opportunity for capacity. The housing market dictates what developers will actually want to build and where. Commercial Drive is a desirable area that can attract high rents and unit prices. Developers will therefore want to build there. Other areas with ‘spare zoning capacity’ may not be as desirable or offer the same return on investment.

    A city is not a water table. It can’t just adjust itself to equalibrium. Unless the mayor and council suddenly allow folks to trade development or zoning rights from anywhere to anywhere, the ‘zoning capacity’ crowd will continue to be either wrong or disingenuous.


  2. An important extra note is that just because a land is zoned for development, doesn’t mean it ever will be built on – as illustrated in the Van Sun a couple days ago: … the lot at Robson and Broughton is used as an example, but there are plenty of others (Granville St downtown has some, Yaletown has several [though at least one of these sites is subject to a fight between city and Concord Pacific], Main St. has several building which have been boarded up and vacant the entire time I’ve been in Vancouver).

    Zoned capacity is moot if someone doesn’t care to build anything in the first place, however, it does appear as ‘available to build land’ if you do the stats, which skews the apparent buildable land tally somewhat.


  3. CityFlaneur said:

    Many of the places being upzoned, such as Grandview-Woodlands, are already relatively dense compared to other areas of the City. West Point Gray and Dunbar and Kerrisdale are all very desirable areas of the City as well – what if they were zoned to be as dense as Grandview-Woodlands is currently?

    It feels like east side of Vancouver is a convenient place to dump density for a lot of reasons. Many of us would like to see more west side areas share the load. Why do those neighbourhoods get listened to when they oppose density increases, but not others?

    Maybe you should be required to rebuilt a duplex every time you knock down a single-family home, instead of another SF dwelling. That might work to ameliorate heritage home loss and waste, while at the same time incrementally increasing density across the City…


    • Frank Ducote said:

      CityFlaneur makes a very good point that merits a larger conversation. What would geographical (zoning) equity look like? Continue densifying already dense communities even further, or distribute the impacts – and benefits – more widely?

      On a related note, the desire to build rail transit through Point Grey (to UBC) would make a lot more financial and even optical sense if TODs were to be planned there, as it has along the entire Evergreen Line.


      • There’s an interesting recent legal precedent from the USA that states if there is de-facto housing discrimination, it doesn’t matter if it isn’t actual de-jure discrimination, its still illegal.

        Applied here, if housing were seen as a right (as it is in Ontario), the argument over where to put density would become somewhat moot, as any policy which was effectively discriminatory (by having the effect of placing all of a certain class of housing in one area) would be just as illegal as actual legal affordability red-lines.


    • Jens von Bergmann said:

      There are areas in Point Grey that are just as dense as the densest part of GW, take the west most Census Tract between University and 16th. Kerrisdale has a CT that is denser than the densest GW CT. Most of GW is less dense than the area north of Broadway between Dunbar and McDonald. Some of that might change after the GW plan, but that will take time. The notion that GW is really dense already is not supported by data.

      Explore for yourself:

      Before requiring building more dense units we should allow denser development on all properties. Our current RT zoning is a complete mess, our RS effectively asks homeowners to become landlords. Some RT areas are zoned for 0.5 FSR, significantly less than RS areas. RS and RT need a refresh.


  4. CityFlaneur said:

    That’s super interesting – it seems the little triangle of land created by Victoria Drive, Kingsway, 33rd Avenue and Nanaimo Street – an area which is mostly SF homes (some apartments on Kingsway) is denser than much of the area adjacent to Commercial Drive north of Broadway, which is not what I’d expect. Is this because the mainly SF area has so many multiple people living together (large, multi-generational families for instance?) versus lots of singletons living in apartments? If considered that way, density is not a reflection of housing form, but people living in whatever form. And if SF houses provide more flexibility for large, extended or multi-generational families that improve density (based on pple per area), then why are we in such a mad rush to build so many high rise condos (like what is going in at Gladstone and Kingsway) that don’t work for families and aren’t affordable anyway?


    • Jens von Bergmann said:

      Multiple suites can add a lot of density. Mostly illegal at this point, would be great if we could do this legally. And design for multi-family 4-plexes instead of stuffing families into basements and not allowing front-facing entrances so we can keep pretending those are “single family” properties.

      You can click into each area (and hit the “more” button to get more detailed info on each area. That triangle has 19% of dwelling units in low rise, which includes buildings with more than one suite. You can also zoom in further and get block-level breakdowns to see where exactly the density is located.


  5. Frank Ducote said:

    If we stay on the subject of ZONED capacity, there is no doubt that GW has vastly greater densities permitted in its zoning districts, with RM (lowrise apartments) to the west and RT (infill with retention of existing houses) to the east of the Drive.

    Pt. Grey’s (Alma to Blanca) residential districts are almost entirely zoned RS-5, which allows a principal residence, a basement suite and a laneway house.


  6. On another PT post someone used the figures 31% of the population living 83% of the land to describe the portion of population living on the area of the city zoned RS. I suspect they included RT as well. No matter. The piece was couched in terms of accepting density in areas that unjustly consume an inordinate amount of scarce land to support so few people.

    I thought the figures also quite magnificently illustrated the geometry of supply and demand and affordability, with or without the catalyst of speculation. Perhaps Seattle has a similar ratio. Geometry is something Elizabeth Murphy and Kerry Gold seem to ignore, along with housing type.

    I believe the geometry will change if cities offered zoning for the missing middle, a large part of which is freehold rowhousing. The keyword is ‘freehold’, and this is the point where housing sticks to the glue of Strata Title Act and also helps lock in unaffordability. The province should be lobbied to amend the act. Even if every attached rowhouse was completely air-gapped from the neighbours, even with separate foundations, they will still be about 1/3rd cheaper than detached homes that come with a 4,000 ft2 hunk of land.


  7. robotboy44 said:

    Since I don’t see the link for it, here is the piece by Elizabeth Murphy regarding zoning.

    Further, the zoning issue is a big distraction propagated by big developers to support their vision of more and more development (and more business for them!). The biggest issue we have in Vancouver around density is the huge foreign capital problem, which we learn more about every day with one astounding revelation after another, from shadow flipping, to money laundering, to tax avoidance to students buying $10 million homes. It goes on and on and it is a huge scandal which impacts our market for owners and renters and our government’s lack of action is as good as criminal, as far as I can tell.

    Address this problem, and zoning issues will not be as severe as they appear to be now. Get the CRA to actually start doing their job, get banks to stop giving preferential treatment to foreigners borrowing without any background checks or questions, get government to actually follow the money and not the individual and get big corporate money out of politics. Put the horse before the cart.

    That’s my rant for the day. Do come to the HALT rally Saturday the 17th at 2pm at VAG to hear more.


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