All FARs are not created equal

At first glance, high-rise Arlington doesn’t seem to permit denser development than DC. The “C-O-Rosslyn” zoning permits a Floor to Area Ratio (FAR) of 10 — equal to the C-4 zoning that covers much of downtown DC, 6th to 19th and Pennsylvania to Massachusetts. A segment along the north side of Pennsylvania, 10th to 15th, is actually zoned for 12 FAR, due to its special 160′ exemption under the Height Act. (This is one of many nonsensical bits within the Height Act; other streets in downtown, like L’Enfant Plaza and the Southwest Freeway, are just as wide and thus in theory present equal opportunities, but their property owners apparently aren’t as well connected as those fine hotels along Penn.)

Yet FAR in DC goes much further than that in Arlington. Along DC avenues, rights of ways typically extend all the way to the building line; front yards are often within the right of way. For example, in Woodley Park, Connecticut Avenue is just 60′ wide — but sits within a generous 130′ right-of-way, which gives it sidewalks ample enough for ambling and dining. Rosslyn, on the other hand, developed rather more haphazardly, and many of its wide roads were widened using easements onto private property. Thus, the FAR granted to a parcel only can be built upon the fraction of the site that is actually buildable, and the same FAR yields much taller buildings. Take a look at the buildable area for 1300 Wilson, just to the left of the middle of this map:

Rosslyn property lines

Similarly, the new street network to be built through the large new developments at Tysons Corner will be built on easements through what’s now private property. Thus, the resulting FARs look low but result in fairly tall buildings. Fairfax’s implementation reports indicate that many of the developments approved or proposed at Tysons’ rail stations are in the range of 4-5 FAR. That’s about equivalent to DC’s C-3 zoning, which is what surrounds Dupont Circle, Judiciary Square, etc. (Yes, that’s substantially lower density than the C-4 in Metro Center, or the C-5 around Freedom Plaza.)

However, in both Arlington and D.C., the high density doesn’t extend very far. For now, most of the newer office areas at the edges of downtown (L’Enfant Plaza, Noma, West End, Navy Yard, Mt. Vernon Square) are zoned C-3-C, or a 6.5 FAR. (The forthcoming zoning rewrite proposes to remove FAR limits for these areas.)

The cloud-scraper in the middle is Living Shangri-La, at the time the tallest building in Vancouver.

By comparison, Living Shangri-La in Vancouver has an FAR of 13.41; most of the shiny new residential areas fringing its downtown have FARs of around 2-3; that’s roughly equivalent to the R-5 zoning around DuPont Circle. Same density in a radically different form. (It’s hard to compare these to other American cities, most of which are wildly overzoned; downtown Chicago starts at 12/16 FAR and goes way up from there; the Sears Tower was built as-of-right.)


6 thoughts on “All FARs are not created equal

  1. It would be interesting to do a little math and see what kind of residential densities you can achieve with a baseline fabric of DC’s R3 and R4 rowhouses, sprinkled with a few apartments, and higher density along main streets (FARs of 6+) – you see this on U Street and along 14th Streetin many places.

    The other question I would want to look into is a hypotheical: assume you could repeal the height limit, but would still be subject to some kind of form-based limit on building envelope. What kind of FARs could you achieve? What kind of density could you gain?

  2. The result would depend entirely on the shape of the fabric it’s applied to, and thus the allocations to public space, “towers,” and townhouses. I suspect that the result would be pretty similar to the “towers & townhouses” of Vancouverism — a typology that was arguably invented in Southwest DC. Yet here, as in many of Vancouver’s point-tower neighborhoods, the result is definitely a subcritical density as far as retail is concerned.

    Similarly, I think that OP mentioned at the zoning-rewrite hearing I went to that FAR already does little to modulate bulk in downtown DC. In their absence, you’d end up with the building-envelope approach that zoning began with oh so many years ago. The eye-popping baseline FARs (15-16) available in, say, Lower Manhattan and the Loop closely resemble the practical limits of those earlier regulations. The Empire State Building and Sears Tower both have FARs exceeding 30, and apparently neither truly maxes out their legal boundaries.

  3. Good points. On the residential side, I think of some places in DC like Columbia Heights where you have a combination of rowhouses sprinkled in with some duplex conversions, basement apartments, etc, and taller multiunit buildings on the main streets. Some census tracts are close to 50,000/sq mi. But yes, my last visit to Vancouver definitely illustrated a lot of the neighborhood retail holes.

  4. I think of how in Chicago, 3-flat neighborhoods are much livelier than the bungalow/2-flat neighborhoods just beyond; none of the latter can muster more than sporadic retail services, for instance. Rowhouses make great fabric — and overall, “ground related housing” avoids a lot of multifamily’s problems — but I do worry that given today’s generous unit sizes, they might fall into the Jacobsean ‘grey area’. (In the comments to that link, Jacobs’ son writes in about the Annex, where he grew up. Despite having blocks of mostly semi-detached houses, its many accessory student apartments yields a density rather similar to the 20-25,000/sq. mi. typical of Chicago’s 3-flat neighborhoods. Plus, it shares its retail strip along Bloor with higher-density areas to the south.)

    Anyhow, this explains some of my fascination with apartment typologies, like walk-up courtyard blocks, that push the envelope a bit in terms of density.

  5. Indeed. I think there’s a big opportunity for some of those housing typologies to introduce greater density in DC without seeming as disruptive as Vancouverism. Take an existing row house neighborhood, and allow Dupont Circle like apartment blocks and a few mid rise (max height for DC) buildings and you’ve got a level of density that can support transit and local retail, while still retaining some of the urban design characteristics of row house neighborhoods.

    I think you could sell that. Selling Vancouverism or greater density might require a focus on one of the remaining large scale redevelopment sites.

  6. Plenty of 3-5 story apartment buildings silently fit amidst existing rowhouses, like the flatirons in Bloomingdale or many on the Hill, but heaven forbid anyone build a third floor in today’s amber-encased neighborhoods. (Come to think of it, there isn’t a single three-flat neighborhood in town. Even Minneapolis has Loring Park.)

    I still think that to be properly transit supportive would still require lots of ADUs on the side streets.

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