Monday, September 26, 2011

Height Limits: The Forgotten Debates

Robert Fogelson's Downtown: It's Rise and Fall, 1880-1950 has a fascinating chapter devoted entirely to the early 20th century debates over height limits in American cities.  The arguments of the opposing sides as late as the 1920s bear an uncanny similarity to some of the recent back-and-forth between Ed Glaeser and Michael Mehaffy.  Although many of the arguments of those in favor of limits at the time have since been debunked (that skyscrapers were more fire-prone, for instance), the most important point of contention, by far, was based not on a difference of opinion, but on a consensus:
"On one point both sides agreed.  If a height limit [in St. Louis, a representative case] as low as 125 feet was imposed, the business district would spread out.  So much the better, argued some.  In the interest of increasing property values, a St. Louis real estate agent claimed, 'It is better to have lower buildings scattered over 15 or 20 blocks than to have a few big buildings in half a dozen blocks.' Not so, responded others.  If downtown St. Louis was spread over a wider territory, it would make it harder to do business in the city.  The more compact the business district, the better."
And in New York: "[A height limit proposed in 1908] failed for another, more baffling reason.  As the Real Estate Record pointed out, a height limit would have spread the business district 'over a much larger area,' and thus would have raised property values everywhere in Manhattan except on or near lower Broadway and Fifth Avenue, where most of the skyscrapers were erected." 
It appears that some agreement existed that a height limit would produce a net increase in citywide property values, and further that this increase would be equitably spread among a large number of property owners, a compelling point which was met by the argument that the agglomeration effects of high density, in concentration, outweighed this loss in values.  The argument of the pro-limit faction, however, necessarily depended on the absence of zoning, for with height limits imposed, the resultant economic benefits could only flow if the business district were permitted unencumbered horizontal expansion into existing non-commercial areas.

In the 1920s, however, the prevailing model of height limits with no zoning was swiftly replaced by a new model of zoning and height limits, except in the existing business core. The exception was Washington, D.C., which retained relatively low height limits while zoning itself into a corner a sure recipe for space shortages and inflated rents down the line (it also did not help that L'Enfant's city plan, with its extravagantly wide streets, left Washington with less downtown buildable area than almost any other large American city).

So which side of the debate was right?  Was there a right answer at all?  It is difficult to know, since there is no large North American city with a meaningful height limit but no zoning that can serve as a point of comparison (European examples are abundant, however).  In a sense the full urban vision of those who advocated for limits is more distant than ever, for not only has the pro-height and agglomeration viewpoint (as presented in its undiluted essence in Triumph of the City) continued to assert itself, but even the historical preservationists whom Glaeser takes to task frequently advocate against horizontal densification, as the lower-density neighborhoods encircling many a central business district frequently happen to be filled with a city's most notable architecture, or most vocal homeowners.  Still, the economic claims of the pro-limit real estate men of the 1920s should in theory be no less valid today than they were at the time, and remain available as a potential, but long-dormant, counter-argument to the economics of the agglomerationists. 

Related content:
A vigorous debate over Washington's Height Act at GGW.

Related posts:


  1. Houston has no zoning to speak of. I can't find out if there's a height limit. Its downtown looks very much like any other American city.

  2. Cambias, Stephen Smith's (of the blog Market Urbanism, i should mention) reply to that business week post pretty much says it all: "It's disingenuous to say that Houston has no zoning without mentioning that it does have strict, minimum parking regulations, strict minimum lot size regulations, and wide streets and long blocks. Though it might not have traditional single-use Euclidean zoning regulations, it does have a lot of strictures that limit density and discourage walkability and feasibility of mass transit."

  3. Cambias -- the only limit I'm aware of is the one the FAA placed on the JPMorgan Chase tower, which was apparently trimmed a few stories in reponse to concerns about obstructing flight paths.

  4. BBnet3000 -- The one thing Houston's regulations do not do, however, is place a limit on the succession of uses -- that is, if Houston's business district wanted to expand horizontally into industrial or residential areas, nothing would stop it from doing so (assuming the inner neighborhoods are no longer subject to restrictive covenants, anyways). Cambias observes that despite this, growth has been vertical, not horizontal.