Jacobs described the process in remarks given at Boston College’ law school:

Yet if the zoning were to be changed to permit dwellings, the developers would be blocked by rules applying to apartments, most especially parking requirements. Land coverage was high and parking couldn’t feasibly go underneath these sturdy but old buildings. Under the guidance of our very intelligent mayor at the time, these and almost all other regulatory controls were removed, except for fire and building safety codes. One rule was added: a ban against destruction of buildings, to prevent aesthetic and environmental waste. You would be amazed at how rapidly those dying districts have come back to life and blossomed. The principle at work here has been the addition of what the previous mixture lacked…

In the case of Toronto’s dying districts of downtown that were revitalized by radically overhauling the regulations, the mayor’s hardest job was goading and re-educating her own planning department, including the youngish man who then headed it.

The results have been breathtaking — and might surprise those for whom Jane is a hero for stopping bulldozers. Not only have the “Two Kings” not lost jobs, as many industrial lands taken out of production have, but the number of jobs has increased by 58%. Even more impressively, 46,000 dwelling units have been permitted in the Two Kings, many of them in very large new high-rises.

Of course, this approach would be much more difficult — if not impossible — to enact in America. It’s not that America over-regulates development per se, it’s that we regulate entirely the wrong things about development. As Jay Wickersham writes in the Boston College Environmental Affairs Law Review, the result is “an extraordinary situation. There is no other area in environmental law where the goals of the regulatory program are not just indifferent, but actively hostile, to the best thinking in the field.” From his introduction:

To paraphrase F. Scott Fitzgerald, Jacobs shows us that Euclidean zoning has been hard where it should be soft and soft where it should be hard. Zoning has been hard, or overly rigid, in dividing our cities and towns into uniform, low-density districts, each dedicated to a single primary use. And zoning has been soft, or overly permissive, in its failure to set design standards for streets, and for how buildings front upon those streets, that would reinforce the fundamental character of streets as public spaces…

Supreme Court rulings restrict municipalities to just two regulatory tools* that can shape development: Euclidean zoning (regulating density and land use) and historic designation (regulating appearance, but only meant for very limited circumstances). Euclidean zoning’s fixation on limiting density and land uses enforces conformity; even when it permits change, it’s only towards a distant, built-out end-state set forth in a comp plan. Jacobs writes:

[T]he greatest flaw in city zoning is that it permits monotony… Perhaps the next greatest flaw is that it ignores scale of use, where this is an important consideration, or confuses it with kind of use, and this leads, on the one hand, to visual (and sometimes functional) disintegration of streets, or on the other hand to indiscriminate attempts to sort out and segregate kinds of uses no matter what their size or empiric effect. Diversity itself is thus unnecessarily suppressed. (D&L, 237-238)…

Instead, Death and Life‘s chapter 13 argues for “zoning for diversity”:

The purpose of zoning for deliberate diversity should not be to freeze conditions and uses as they stand. That would be death. Rather, the point is to insure that changes or replacements, as they do occur, cannot be overwhelmingly of one kind. (D&L, 253, emphasis added)

Jacobs was not against regulation, but as an empiricist she held tremendous regard for the way cities had evolved as complex systems over the centuries — and fought the woefully simplistic (and completely ideological, perhaps even “faith-based”) Modern-era planning regulations and programs then in place. Alas, those regulations remain at the foundation of American planning today. Wickersham again:

According to Jacobs, “[a]ll zoning is suppressive,” an interference with the unfettered movements of the real estate market. But Jacobs is not attacking regulation, per se, or even the notion of government planning… she is attacking the functionalist presumptions shared by many city planners. In this view, a city is a functional, repetitive machine, rather than an ever-evolving organism… Her goal is to strike a middle course: to preserve and enhance diversity by avoiding large-scale, cataclysmic physical and social changes (which can be caused by rapid influxes of private investments, as well as by publicly sponsored urban renewal projects), without permanently freezing a community’s character.

Density-and-use zoning is the metaphorical hammer of urban land use: every potential problem ends up looking like a nail, and gets hammered to smithereens. It doesn’t matter if the problem has nothing to do with density or land use, and it doesn’t matter that density and land use are (as the Kings show) pretty darn incidental to the grand scheme of things. The only tool that we have is the wrong one, but we’re going to use it anyways. Wickersham notes that even the modest attempts to circumvent Euclidean zoning through discretionary approvals, or worse yet to somehow require diversity, are doomed to failure from Jacobs’ perspective:

Because these reforms are project-specific, and not comprehensive, the counter-productive, as-of-right requirements of Euclidean zoning have been sidestepped, not removed. To tempt developers into the project review process, regulatory systems will offer a density or height bonus to offset the increased time and costs that are involved. Such incentives can cause all parties to undervalue small-scale, incremental renovation and infill projects—the incremental reinvestments that Jacobs showed us were so important for the stability of an urban district. Thus, favoring large private investments can cause the same kinds of cataclysmic change that Jacobs decried in the public urban renewal projects of the 1950s.

Update: Shawn Micallef has a fantastic summary of Jane Jacobs’ Toronto legacy on Curbed today. The headline of this post spoofs Spacing Store’s #WWJJD t-shirt.

* Non-regulatory tools, like redevelopment, are also legal but are so difficult and fraught with such complexity that they’re unlikely to have a substantial impact on regional-scale land use challenges. Form-based codes are the most promising alternative to Euclidean zoning in the US, but in practice require such a radical overhaul of the planning-and-zoning process that they have yet to achieve wide adoption; Miami is the notable exception that rewrote its plan and zoning code all at once.

(Top photo by chensiyuan)