Zoning, the Static City, The Dynamic City

At the beginning of the year, Charlie Gardner at Old Urbanist offered an academic's findings on zoning, especially where American practice is in conflict with European practice. Perhaps the most important part, however, is a paragraph buried deep in the piece:

How this exceptionally American land-use system came into being during the late 1800s and through to the 1930s is the primary focus of Hirt's book.  In chronicling this period, many apparent paradoxes present themselves: for instance, although the United States of the late 19th century prided itself on being the most democratic nation in the world, its citizens had a low level of trust in their elected municipal officials.  The progressive municipal reformers of the time might therefore have campaigned for planning to be guided by state or federal governments, but instead pushed for non-discretionary municipal-level zoning.  As Hirt observes, zoning reformers such as Lawrence Veiller argued that "zoning rules should vary as little as possible in districts that were as large as possible and that zoning relief should be granted only under a very limited set of circumstances, if at all." 

But if the planning powers were delegated from state to city, and the city was to have little power to alter the apparently infallible choices of the initial zoning commissions, who was left to actually engage in city planning?  No one, as it turns out.  Planning commissioners were seemingly intended to be little more than curators of the city zoning map, and Hirt finds, as I have also noted, that zoning maps have changed relatively little in their basic allocation of space since the 1920s.  As I've written about before, the actual policy that zoning was intended to serve was almost an afterthought, and was primarily concerned with protecting the investments of wealthy homeowners.  By default, and perhaps unintentionally, city planning (to the extent it existed at all) was turned over to the emerging highway engineering profession. 

American zoning policy, in sum, was a negative and reactive vision -- through its implementation, it viewed cities as incapable of honest and effective self-government, and by its actual regulations, it viewed urbanization as a threat to not only investments but to civic spirit and even the American way of life itself. As Hirt writes, "[t]he single-family home had the right to the city: it was always seen as being there first. It was the gracious host, the delicate victim, and the original citizen that was always haunted, followed, invaded, and taken advantage of by other housing types." In this sense, Hirt's book echoes the conclusions of Steven Conn's recent Americans Against the City: Anti-Urbanism in the Twentieth Century.

The key takeaway of this is fairly simple: American zoning was already being used as a tool to prevent redevelopment as early as the 1920s. Zoning theory, while it grew out of nuisance law and European (especially German) practice, was already being adapted to exclude rather than include -- zoning, by design, is a hyperlocally-devolved tool. Indeed, the basic idea seems to have been to zone land such that intensification of existing development was made impossible, a practice which inevitably would concentrate redevelopment in the most intensively-used areas -- and on the greenbelt edges. 

And because there was no systemic planning practice designed to rezone, it has been left to politicians' whims, which often result in downzonings once communities realize that existing zones allow more intensive land use than what currently exists, and state DOTs -- whose highway extensions (and not mass transit extensions) have been, since midcentury, what has opened new land up to development.

What is curious to note, then, is that American sprawl is driven by what is essentially a units problem. In the hard sciences, units problems rise when units are misapplied, or when they're inadvertently mixed. For example, while a velocity calculation might be mathematically simple under constant acceleration, the result has to be in the same units as the inputs (e.g. m/s, cm/s, mi/h, etc.). Mix up the units -- say, by measuring an object's weight when what you want is its mass -- and you throw your calculations off. Similarly, inappropriate aggregation can often hide more than it illuminates: this is one of Jane Jacobs' key critiques of mainstream macroeconomics, that the sovereign nation is fundamentally an inappropriate unit for economic measurements, as it almost always represents an aggregation of very much economically disparate regions. 

By over-empowering land use planning at the hyperlocal scale, we inadvertently disempower reasonable land-use planning at the scale where it matters most, as far as optimizing spatial efficiency relative to amenitization is concerned: the greater conurbation. Static land use paradigms undercut the efficacy of mass transit (as has often been pointed out at Urban Kchose); because zoning law is not designed with spatial efficiency in mind -- and, indeed, almost every solution to any given land-use problem increases spatial inefficiency -- we find ourselves unable to respond save by sprawling more ... and more ... and more.

Sometimes small-scale intensification is not aesthetically pleasing: witness D.C.'s pop-up house, which, now that one has been built, has been banned. Indeed, this has generally been zoning's modus operandi -- regulate nonconformity into nonexistence. The problem with this is, however, that at a certain level, small-scale intensification requires aesthetic flexibility. Indeed, this may be old urbanists' strongest criticism of New Urbanism: that it overfocuses on form, while underfocusing on the land-use development process -- the true locus of the sprawl process. This is perhaps where Strong Towns has come into play: it has gained traction and has been growing, as a grassroots movement, precisely because it has correctly identified the core problem: a broken process: a process that enshrines a static, rather than dynamic, vision of the city.

But here is an interesting issue, and once where there might actually be natural friction between Strong Towns and old urbanists: short of total curtailment of land use regulation (an extremely libertarian solution), while the issues in transportation engineering are clearly defined by its excessively top-down paradigm, the problems with spatial planning are caused by it being excessively bottom-up. That is, resistance to change is driven not by new inhabitants but by the ones who already live there, and have the time and energy to mount opposition (which, due to the way the playing field is skewed, is almost always effective opposition). Even very simple changes -- for example, liquidation of excessive parking regulation, making small multiunit structures legal, moderate height increases, and other examples of incremental redevelopment -- are opposed so fiercely that, outside of large urban cores where an effective development counterpresence can be built, they are unlikely to get any traction.

The long and the short of this can be summed up by saying: The current land-use planning paradigm is fundamentally broken. Moreso, it is fundamentally broken because current American regulation creates a static vision of the city, rather than a dynamic one; this fundamentally empowers interests that favor their static vision (NIMBYs) while disempowering ones whose vision is dynamic (developers). And, despite many planners' attempts to make dynamic redevelopment easier, the truth is that the discipline's entire toolkit, over-oriented towards a static vision, greatly inhibits what can be done, and yields marginal results of even the most sweeping efforts.

My Train Of Thought Is Going Over Wind Gap, Apparently

Saw this item on Systemic Failure the other day: http://systemicfailure.wordpress.com/2014/02/24/vre-replaces-apartments-with-parking/

Progress on acquiring land in the Crossroads Business Park for the 1,500-space parking lot at the planned station is moving along more slowly. Officials had originally expected the station to be open by now, but numerous issues have popped up, with the most recent problems caused by stalled negotiations for land for the commuter parking lot.

The county had been negotiating with businessmen George Lester and Fitz Johnson, who own the property needed for VRE parking. The businessmen recently gained county approval to build 610 apartment units and commercial space next to the station site.

But the negotiations for the roughly 25 acres for the parking lot have proven fruitless. So the county recently asked the Virginia Department of Transportation to handle the property acquisition.

“They can facilitate it better,” said Spotsylvania County Administrator Doug Barnes. 

Ya think? And what's worse, there are plenty of excellent examples where it's Done Right nearby--in Arlington County, in fact.

But there is another issue buried between the lines here. 610 apartment units on a 25 acre site comes out to 24.4 units/acre. Let us simplify this to 24 u/acr, and consider that postwar "garden" apartment "barracks" are really just attached rows of duplexes or triplexes in "green" settings*. At 24 u/acr, you get (a) 12 dp/acr, or 1 duplex = 1/12 acr, and (b) 8 tp/acr, or 1 triplex = 1/8 acr. Triplexes cover less space, yielding more green space, so this complex would probably be triplexes.

Let us, by contrast, begin with the typical 25'x50' lot found in prewar suburbia, remembering of course the dictum that there is no difference between New Urbanism and prewar suburbanism. Since an acre is slightly greater than 200'x200', this implies that there are 32 lots/acre; triplexing this yields 96 u/acr, or twelve times the density of what is currently being achieved. But this is excessively dense; most railroad suburbs have emergent 50/50 homeownership/rental ratios.

Let us reserve, in line with typical consumption, 20% of our site (5 acres) for infrastructure--streets, a park, and the like. This yields 640 lots on a 25-acre site. Splitting these lots evenly, we have 320 houses and 320 plexes. Splitting the plexes evenly yields 160 duplexes and another 160 triplexes**. Summing these yields 1920 units, a whopping 315% more than the current proposal calls for. And furthermore, neighborhoods built out to this density are often just as green, and charming, as those with more green space. This implies that, past a certain amount, provision of green space is subject to diminishing returns: Just before you hit it, you get charming "green" town environments; past it, house farms.

So provision of green space is clearly not a good in and of itself. Like most anything else, it's how it's used that determines its true value. Green scraps left to fulfill zoning requirements have marginal development value and zero usage value. But modernist planning, in its flawed assertion that green space is an unmitigated good, makes no account of this. This is why house farms and towers-in-parks both tend to have the same overengineered, lawn-softened, bleakly industrial look: They are both people batteries. And because urban dynamics requires a critical mass to spark, while the lawns hide their interiors' aesthetic bleakness, they also push everything too damn far apart to spark emergent urban dynamics.

Anyway. Since the average household size today is 2.6, our 25-acre railroad suburb would yield a population of ~5000, a much fatter prize than the ~1600 the garden apartments would house, and certainly a far fatter prize than a 1500 space lot. Three other similar developments nearby would yield a nice town of 20k on 100 acres...

Modeling, the fact that, past a certain critical point, green space appears to cease to boost urbanism, and indeed, instead diminishes it needs to be considered mathematically. This critical point appears to be tied to an urbanism "critical mass". Since critical masses imply step functions, we can infer Heaviside (either it is or isn't), and can also infer that that function's discontinuity occurs at a certain percentage of green space provision. Since green space provision, by percentage, is (obviously) along the origin from (0,0) to (100,100), all we need to find is at what value green space provision, by lot, definitively hurts the formation of urban dynamics. This implies a Heaviside step from 1 (urbanism is emergent) to 0 (it is not).

Urbanism also has a clear financial buff. We need to find the nature of this buff (is it scalar? vector? etc.) and model it; knowing this information can help develop key Strong Towns tools that are not just descriptive, but predictive as well.
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*By stacking, not by firewalls. By firewalls, you can get du-, tri-, quad-, and hex- (6) plexes. Quadplexes by stacking (octoplexes, or 8 units, per firewall) are rare, but not unheard of; pentaplexes (5 units) by stacking and their decaplex (10 units) cousins by firewall are absent--most likely because elevator regulations start kicking in at that point.
**There are a couple of reasons for doing this. First off, different space requirements. Duplexes have more living area than triplexes in a unit shell. Secondly, this yields a Main Street of duplexes atop commercial units. But it is unreasonable to think the Main Street would consume all of the allotted duplexes.

Railroad Suburbia 2.0

A lot of the New Urbanist corpus--particularly the town planning elements--focuses on the traditional town planning model. Their ultimate desire is to build communities like these:

Now the thing is the communities the New Urbanists have built

have tended to look a lot like

each of which happens to be a railroad suburb.

Railroad suburbs were primarily developed during the Victorian era, fin-de-siècle, and into the 1920s. Aping developers' success in using streetcar lines to sell new housing, several railroads decided to enter the development game themselves and build "New Towns" lineside. This pattern--small, semi-dispersed centers of population highly centralized around train stations (a major railroad suburb giveaway is when a train station lies at one end of Main Street) became a primary mode of outward urban expansion for the better part of a century, and has left us a rich heritage of the nicest, leafiest communities in cities all across the nation. And, despite catastrophic disinvestment in anything that wasn't a house farm from the 1950s to the early 2000s, railroad suburbs continued to be the effective archetype of quality American community.

(And sometimes they became something more.)

New Urbanism got its start replicating railroad suburbs as new towns--even if the original railroad discontinued passenger service, the railroad suburb is, for all intents and purposes, a new town. Duany and Plater-Zyberk folded in some Southern Baroque town planning tradition, and--voilà!--an alternative to house farms, Levittown tracts, and meandering anti-grids was born.

There are profound implications to this. First, one of the great successes of the movement is the re-creation of the railroad suburb. Transit-Oriented Development, an idea about as old as New Urbanism, is (in essence) a manner of development built on the workings of a railroad suburb.

In the eventuality transportation policy changes--as it must, if Italy is at the vanguard of the trend--we have reclaimed the development model associated with a smaller, smarter, more compact type of urbanism and town-building.

The key becomes, then, developing the right transportation policy: Most cities have enormous wealths of historical (largely disused) potential commuter rail lines--lines on which, were they active, we can hang New Urbanist (re)developments and intensification...These should be the avenues of growth in metros.

Suburban, Exurban, New Urban South Philadelphia

Note: This post originally appeared Friday.

The deepest part of South Philadelphia, south of the Schuylkill Expressway, is full of surprises. An Olmsted park graces the corner of Broad and Pattison–as does the NovaCare Center. The most most of us ever see of this area is the Sports Complex, or, if we work there, the Navy Yard.

But behind the Navy Yard lies a swath of (mostly) post-war residential development that reflects the changing perception of ... Continue reading at Hidden City Philadelphia.

Quick Note on the History of Urban Planning

Nostalgia* has been behind almost every movement in urban planning.

1. City Beautiful. Nostalgia for the imperial center, as established in Mesopotamian, Greek, and Roman precedent, and retranslated in the Baroque period.
2. Decongestion (for lack of a better word). Nostalgia for the idealized medieval free city. We can see this in Ebenezer Howard's Garden Cities of Tomorrow and especially in Lewis Mumford's The Culture of Cities.
3. New Urbanism. Nostalgia for the settlement pattern nebulously called "Small Town America". Resultant reduplication of features common to this settlement pattern, with the sole exception of abandonment of the strong grid. Outgrowth of urban theory of Andrés Duany and James Howard Kunstler; informed greatly by Christopher Alexander's A Pattern Language.
4. Landscape Urbanism. Nostalgia for Modernism, primarily as an interbellum movement. Led by Charles Waldheim and James Corner. Nostalgia for Frederick Law Olmsted and Le Corbusier.
5. Traditional Urbanism. (Why is it even on here? Because it's the most cogent response to New Urbanism there is, despite its lack of attention in intellectual circles.) Nostalgia for castle towns (for lack of a better term). Nostalgia for density. Articulated best by Charles Gardner and Nathan Lewis. Informed by Jane Jacobs. Desire to harness urban forces operative in e.g. informal settlements.

There are only three major urban theorists who I can think of who are members of no movement--two of whom are Jane Jacobs and Christopher Alexander--and it's precisely their work that has stayed most relevant through the years. This is frankly because both of their work starts by correctly identifying the problem of the city (a precious rarity in urban theory) and works from there. The third theorist is, of course, Le Corbusier, whose ideas (the Radiant City) have been, by and large, discredited.
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* By nostalgia I mean the idea of a historical urban form as the ideal urban form. There's nothing wrong with that--humanity has experimented with a variety of urbanisms throughout its history, and relatively few have failed. Charlie Gardner pointed out that he's trying not to romanticize, and a laissez-faire approach to urbanism should theoretically lead to a variety of urbanisms; one of my larger points, both in agreement and in contrast with him, is that there are a variety of good urbanisms. Of the schools I pointed out, traditional urbanism comes closest to reflecting this--possibly due to its youth.