Thursday, May 26, 2011


Philadelphia's Planning Commission is rewriting its zoning code. It's been a long time coming--the Code was last completely revamped back in 1960, and has accreted so many amendments that it's exceedingly difficult, in some situations, to even determine what exactly the Code says about a parcel--and will largely be either no change or a positive change, in terms of what somebody can do on a parcel. (The new 25% deviation rule, for example, will help cut variance requests, especially on grandfathered buildings, such as mansards, too tall under the 1960 code, by quite a lot.)

But the strangest discussion about the Code, to me, has always been about the densest districts.

Philadelphia's maximally dense zone is C5, which would become RC5 under the new Code, the zone of the core of Center City, among other places. Areas zoned C5 (RC5) look, in the main, like the cap over I-90 in Boston's Back Bay, or Chicago's Loop, or downtown San Francisco, and especially like Midtown Manhattan. (The grid precludes Lower Manhattan.) Average height in Center City's urban core is 20 floors, with some exceptional structures, such as the Comcast Center, BNY Mellon Center, or Liberty Place, marking the skyline from afar.
C5 (RC5)-zoned area

Which is why I find it so odd that C5 (RC5)'s base zoning is for 1200 FAR.

FAR is an acronym for Floor Area Ratio, and describes the maximal height (by stories) on a maximally-covered lot. A FAR of 1 would allow a one-story building to completely cover the lot; 1200 FAR therefore allows for maximal lot coverage of 12 stories. The Wanamaker Building, which is actually 11 stories but completely covers its lot, is usually used as an exemplar of a 1200 FAR structure. Other rules, relating to Philadelphia's height-bonus system, also describe what kinds of uses are included and excluded in FAR description (retail podiums are excluded according to current bonus standards, while public space (outside) and public rooms (inside) both qualify as open space, for example.)

Even with this considerable leeway, however, something is rotten in the state of Denmark, and the 1900 Arch apartment proposal tells us what.

1900 Arch is a proposal for a 19-story apartment building with two ground-floor restaurant pads and underground parking: a proposal that makes intuitive sense. The layout is essentially a latter-day interpretation of a classic garden apartment, with wings along Arch and Cuthbert streets enclosing a pocket park space in the middle, which would be used for (among other purposes) outdoor seating for the two restaurant pads. Some people think it's ugly, but de gustibus non disputandem and à chacun son goût and all that. So far, so good.
1900 Arch

What is mysterious is why this project has to get a variance at all*. The site is a lot in the densest part of Center City, a mere two blocks from the Comcast Center, BNY Mellon Center, 2 Logan Square, and the Bell Atlantic tower, among others; it would be a dense building among other dense buildings. And it--surprise surprise--is being opposed by a group of NIMBYs from a nearby condo, complaining about things such as "air" and "light", which is, let's be honest, just cover for "I don't wanna hear construction noise for a year".

1900 Arch should be regarded as the typical Center City project. Its density is context-reasonable**, it offers ground-floor retail and some green space, and it hides its parking--the bottom line, it behaves well. This is exactly the type of building we should be fostering, by making construction of it and others of its ilk as streamlined as possible. It should not need to get a variance. Why, then, does it have to?

Even at 1200 FAR, Philadelphia's densest zoning is not dense enough to adequately describe Center City's densest areas. While yes, there is a need for variances and bonuses and all that usual horseplay when something that impacts the skyline is proposed, for a project like this, with (among other things) minimal skyline impact, there should not be a need to go through ZBA and the Planning Commission. Rather, C5's maximal FAR should be 2000 (20 stories), which would permit as of right more infill apartment projects of this type, which, in its turn, will eat more of those pesky Center City parking lots*** that just seem to always stick around.

Assuming (R)C1 and 2 stay constant, I would suggest that the (R)C section of the Code be revised as such: RC3, 500 FAR; RC4, 1000 FAR; RC5, 1500 FAR; and RC6, 2000 FAR. This way, once FAR kicks in, increasing structural density is a given. The kind of thinking that gave us a C5 with 1200 FAR is exactly the kind of 1960s thinking we want to be rid of--not promulgate.
* Well, okay, technically the site's zoned C4, the penultimately maximally dense district in the City of Philadelphia, but with a FAR of 500, the dropoff sure is quick. This also serves to demonstrate the antiquity of the zoning map as a whole, since the site hasn't called for a C4 zoning since 1970 or so, certainly not with the Sterling and Kennedy House right next door.
** As opposed to, say, Northern Liberties' American Loft, a maximally-dense type building in a neighborhood characterized by rowhomes and industrial-scale lofts.
*** Such as (in no particular order) 1450 Chestnut, 1301 Market, 800 Market, 900 Chestnut, 951 Sansom, 1300 Arch, 1401 Spring Garden, 800 Race, 2201 Market, 2250 Market, 68 N. 23rd, 3000 JFK, 3001 JFK, 3001 Chestnut, and so on.


  1. Ugh, this is very bad news. We're literally stuck in the 19th century – there were building taller buildings in 1890, for fuck's sake!

    The truth is that these unreasonably restrictive codes work in politicians' favors. Variances are the politician's best friend, they can basically buy votes with the concessions they get. A more realistic zoning code that actually allowed what is reasonable deprives politicians of these ad-hoc extortion exercises, which robs them of guaranteed votes, which of course they will never vote in favor of.

    - Stephen Smith,

  2. I'd say it's the RC4 rule that's the problem here, not the maximum imposed by RC5. The FAR permitted by the most permissive residential zoning in New York (R10) is 10; the most permissive commercial FAR is 15. Expanding the RC5 zone out to encompass all of Center City and the dense neighborhoods abutting it should suffice. Of course even 12 is too low for a CBD, and commercial zoning should allow more (the Empire State Building's FAR is 33), but it's probably a less urgent matter.