A Modest Proposal for Zoning in Tennessee

Just a week after I wrote about Nashville's new downtown zoning ordinance, news has come in that Tennessee's General Assembly is considering a law that would have a dramatic impact on zoning at the city and county levels.  Among proposed changes that would strengthen protections for non-conforming uses is this brief provision:

"No private property shall be rezoned by any local government without the express written consent of the property owner or owners." (S.B. 1272.)

The bill's prospects are uncertain, but it has Nashville's city government worried enough to issue a recent memorandum noting that the law "would essentially prohibit any large or overlay zoning (including a county-wide comprehensive rezoning) unless all property owners agree."

That may be an understatement. The practical difficulties in obtaining written consent from more than a handful of owners would probably put an end to almost all rezonings, not only those of large areas. Selective rezoning would be a certain path to lawsuits and allegations of favoritism and spot zoning. To the extent that any rezoning would be possible, it would be far easier in exurban greenfield sites than in built-up areas.

It would be interesting to see how Tennessee courts would react to this law were it enacted. An Arizona law similarly requiring landowner consent for downzonings was struck down by an Arizona Court of Appeals in 2002, which wrote:

"[T]he [law] affirmatively grants property owners the ability to prevent counties from initiating downzoning of the owners' property ... , thereby effectively delegating to those property owners the downzoning authority that formerly reposed in counties. However, it is a well established theory that a legislature may not delegate its authority to private persons over whom the legislature has no supervision or control." McLoughlin Realty, Inc. v. Pima County (2002).

The court also noted that "a county's planning power is not merely ancillary to its ability to rezone; the two powers are interdependent. Only with the authority to rezone property can a county effectively make the extensive planning determinations required of it."  In effect, the zoning power, deprived of the authority to rezone, is no power at all.  The legislature can withdraw it altogether, the court held, but it cannot delegate it to private citizens.   (Arizona has since adopted a new consent law, § 11-814, which has not yet, as far as I can tell, been challenged in court).

Oddly, the idea of selectively or fully repealing zoning  – a perfectly legal course of action – seems not to have gained any traction even in such ostensibly pro-property rights states as Arizona or Tennessee.  Arizona's libertarian-supported Proposition 207 focused on declines in property value resulting from rezonings, while avoiding the broader point that it is zoning itself that serves as the greatest suppressant of
both property values and the free use of land.

Why is this alternative (not that I am necessarily advocating it) so infrequently raised by property rights advocates? Do libertarian principles perhaps yield to a strong personal preference for low-density, use-segregated single-family zoning and fears of change? Are restrictive covenants, in spite of the example of Houston, seen as an inadequate stand-in? And why cast the language of these statutes in terms of landowner objections to city rezonings, rather than granting owners the right to obtain rezonings on their own terms?

I'm not sure of the answers to any of these questions, but regardless of the motivation, the approach pursued by Tennessee and Arizona lawmakers threatens to bring about the worst of both worlds: a system that has all the rigidity of Euclidean zoning but none of the adaptability.


 Related posts:
 Did Zoning Ever Preserve Property Values?

Friday Read: Lewis Mumford on Narrow Streets, Wide Streets, and the Car

Several months ago, I excerpted a few passages from Jane Jacobs' work addressing street width.  As it turns out, one of her great antagonists had even more to say on the topic: not Robert Moses, but Lewis Mumford, whose scornfully-titled rebuttal to The Death and Life of Great American Cities came only a year after the publication of his own magnum opus, The City in History.

Mumford's own views on urbanism didn't fit neatly into any single category of his day, or ours.  While he abhorred the industrialized city, he was also a vocal opponent of sprawl; in the heyday of highway building, he singled out the interstates as the destroyers of cities; he wrote admiringly of the medieval town, yet the garden city forms he advocated bore little resemblance to 13th century Bruges or Siena.  His concern with congestion was in many ways a relic of the 19th century, yet his opposition to the effects of the car anticipated the 21st. His idealized conception of small town America, meanwhile, foreshadowed the rise of the New Urbanism in the early 1990s.

Still, like Jacobs, Mumford was a perceptive observer of the urban form, and even in a book covering some 5,000 years of urban history, few details eluded him. On the functional benefits of narrow streets, both in northern and southern climates, using what we might today call "original green" techniques:

"Not by accident did the medieval townsman, seeking protection against winter wind, avoid creating such cruel wind tunnels as the broad, straight street. The very narrowness of medieval streets made their outdoor activities more comfortable in winter. But likewise, in the south, the narrow street with broad overhangs protected the pedestrian against both rain and the sun's direct glare." p. 308

In response to Corbusier's derogatory reference to emergent street plans as the product of "donkey paths":

"Those who refer to the winding streets of such a town as mere tracings of the cowpath do not realize that the cow's habit of following contours usually produces a more economical and sensible layout on hilly sites than any inflexible system of straight streets." p. 301

Following a discussion of the relative space allotted for public buildings and streets in L'Enfant's plan for Washington D.C., and observing the "absurd" ratio between the two, he noted:

"The other fact that redeemed L'Enfant's original plan, though it did not add to its beauty, was the filling up of the overload of wide streets with sufficient wheeled traffic to justify their existence: this came in only with the motor car. Though motor traffic has now caught up with the plan, clogging the most extravagant arteries, and hiding the verdure behind a wall of parked cars, Washington has proved a classic testing station for the question of whether a city dedicated wholeheartedly to traffic could sufficiently survive for any other purposes." p. 408

In the case of Washington, it was a test which was cut short when, some years later, the city cancelled the majority of its ambitious plans for a downtown freeway network and instead began the construction of Metro.

Finally, Mumford was one of the few writers of his time to note the "heroic materialist" aesthetic underlying the design of the streets of 19th century American cities:

"Even where overcrowding of the land did not exist – for example in many of the smaller towns of midland America – the broad street or avenue was valued as a symbol of progress: so that it was laid out with an amplitude that bore no functional relation to its present or its potential use. . . ." p. 427

Ultimately, Mumford's keen eye for urban details and his appreciation of the medieval city did not translate into a direct advocacy for anything resembling medieval urban form, which he apparently considered excessively dense. Still, the derided superblock, the setting for dozens of the garden-style housing projects that Mumford advocated, was with its approach toward the car perhaps more sensitively designed than the current historical narrative would have it.  Of all Mumford's observations, it is his identification of the car, or rather the prioritization the needs of the car in urban planning decisions, as the greatest long-term threat to the health of the city, that seems to resonate most strongly today.   

Related posts:
Jane Jacobs on Narrow Streets

Parking Minimums, Most Zoning Left Out of Nashville's New Downtown Code

Having lived for three years in Nashville and developed a fondness for the place, I was glad to see the city get some coverage in a recent  post by Kaid Benfield on the city's plans for developing a regional transportation network.  In addition to its plans for the region, Nashville has revamped its zoning code, adopting in 2010 what is in substance, if not in name, a form-based code for its downtown.  The changes are some of the most promising I've seen in any code revision for a major American city, including the repeal of most of use-based zoning limitations and the elimination of all parking minimums within the downtown area.  It's a long overdue change for a downtown with a particularly tragic 20th century planning history.

From the BIG Map Blog

An 1860s view, at right, shows a city built densely along the Cumberland River, with the city hall and courthouse placed in the center of a large square (the Public Square).  The state capitol building sits on the point of highest elevation, just north of the main commercial area.  The grid was less rigorous here than in some cities, with a variation in street widths and an allowance for adaptation which permitted the emergence of alleys and narrow streets along and across blocks, resulting in a  fine-grained urban fabric.  Even as early as this era, however, a trend toward a city of detached single-family homes is clearly evident.  The path of the railway line, meanwhile, anticipates the subsequent blighted industrial belt and inner ring of Interstate 40.

The Public Square circa 1890.

Nashville was one of the first cities to pounce on urban renewal funds following the Housing Act of 1949, acting swiftly to draw up plans for clearing large swathes of the city (clearance work around the capital had been ongoing since the 1930s).  The Public Square, seen as decrepit and impeding downtown business retention, was obliterated: the courthouse and town hall were torn down, and the buildings surrounding it razed.  Along its margins, a new bridge carried six lanes of traffic into a widened Union Street.  An intricate network of alleys was neglected or abandoned, leaving Printer's Alley, a one-block stretch of shared space traditional urbanism, as a reminder of the past. Poor residential neighborhoods surrounding the downtown were cleared en masse and rezoned for industry in an attempt to retain the city's manufacturing base.

In the desolate landscape resulting from this policy lies opportunity for Nashville and for other cities in similar situations, since the same land which was cleared has remained largely fallow in the intervening decades, leaving it a blank slate largely unencumbered by NIMBY opposition.  The image below shows the area, Sulphur Dell, immediately to the west of the downtown (west is up) where lately a few apartments and townhouses have begin to sprout amid vast areas of surface parking:

The piecemeal development occurring prior to 2010 has not necessarily come together to create a compelling urban environment, as setbacks and parking requirements have combined to result in fragmented development with little sense of spatial enclosure. 

The new code explicitly acknowledges these shortcomings, noting that "while residential development has thrived in recent years, the creation and enhancement of urban neighborhoods is still a goal."  In line with this, some of the most significant changes in the code include:

• The entire elimination of parking minimums, without the imposition of maximums (p. 80; Market Urbanists take note).  This shames the much-touted Miami 21 code, which has retained high minimums. 
• A de facto abolition of Euclidean zoning.  Although a use chart is presented in hyper-detailed Euclidean format, virtually all uses, except for heavy industrial and some automotive businesses, are allowed, essentially creating a "general urban" zone along the lines of those found in Paris (p. 57-58).
• Abolishing most setback requirements, and instead requiring that buildings occupy at least certain proportions of their street-facing frontage. 
• The establishment of height limits, with bonuses for incorporating certain features, including LEED certification, open space, certain types of parking (underground or above ground but "lined") and affordable ("workforce") housing.

The first three of these are remarkable achievements in contemporary planning and zoning, representing a reversal of almost 100 years of planning policy and a liberation of basic property rights long held hostage by the city.  The height limits – anathema to some, I know – may help cut down on the high-rise land speculation that is rampant and impairs development throughout the downtown (paired with a land value tax, the benefits would be greater still).  Even so, there are elements here that either undermine the stated objectives of the code or could be strengthened:

• Height bonuses: most are well-intentioned but counterproductive.  A bonus for public "open space" reflects a suburban aesthetic and incentivizes the tower-in-the-park form, contrary to the stated goals of the new code.  A bonus for certain types of parking would appear to incentivize parking, even if the code does not require it.  If there are no parking minimums, why not provide a height bonus for little, or no parking?   Or only underground parking? 
• Streets and blocks: to its credit, the code addresses this issue, proposing a handful of new streets to improve connectivity in certain areas.  As can be seen in the above image, however, the existing street network is, in places, grossly inadequate, with overly wide blocks and insufficient north-south streets.  The urbanization of this area, if it is to be effective, will require the opening of many new streets to bring blocks down to mangeable, pedestrian-friendly dimensions.  Existing plans are too tentative.  Narrower streets would have an important role to play here. 

Despite these drawbacks, Nashville's new code for downtown is a remarkable achievement, and ought to serve as a model for cities like it, or for any cities, for that matter.  Expanding it beyond the downtown area would be a major next step, but the selective loosening of regulatory constraints in that one location may encourage a beneficial funneling of real estate investment into long neglected central areas.

Related links:
The Nashville Civic Design Center, which is staffed by some dedicated urbanists, has spent years working on plans for downtown neighborhoods, and has a wealth of articles, photos and plans on its website for those interested.

Greening the DC Zoning Code?

The newly released draft of Washington DC's zoning code, as reported by Greater Greater Washington, contains promising changes, including reduced parking requirements and the allowance, after a decades-long ban, of homes on alleys.  Also new to the code is the proposed "Green Area Ratio," a regulation that is molded on similar laws found in European cities such as Berlin and Malmo.  A version of the same idea, the so-called "Green Factor," has already been implemented in Seattle, where it has drawn praise and some criticism. 

The basic idea of the GAR is this: in order to address a perceived imbalance of paved/built to green space in urban areas, the zoning code must mandate dedicating a certain proportion of each lot to landscaping or permeable surfaces.

 According to its proponents, the GAR will push buildings to better treat stormwater, improve air quality and reduce urban "heat islands." However, the draft regulations do not appear to contain any standards to determine whether landscaping elements actually aid in stormwater retention or treatment. Nor is there information about whether the estimated benefits are large enough to matter regionally or city-wide.

Existing research also raises potential concerns that nobody will monitor the environmental performance of these features once built. George Washington University professor Melissa Keeley, whose work the draft documents cite, sounds a cautionary note about "policy deficits and the lack of adequate outcome monitoring" in her 2011 study of Berlin's green ratio.

Some of the benefits seem questionable, like the statistic that "1,000 square feet of green roof can supply 110 people with oxygen." While this is beneficial, that the carbon monoxide-emitting motor vehicle creates much more pollution in urban areas than the lack of landscaped surface.

Berlin's air quality, which some sources estimate is the cleanest in Europe, largely owes its success to car restriction zones and policies that encourage traveling by foot, bicycle and mass transit. Cities are unlikely to substantially improve air quality without confronting the role of the car.

Additionally, GAR does not appear to distinguish between non-green ground coverage. An asphalt-covered surface parking and a 10-story apartment building with no parking and which covers its entire lot both receive a GAR of zero. On the other hand, it appears that the same apartment building with a 160-car garage but with a green roof could earn a high GAR.

The most notable element of the GAR is, perhaps, what it does not include. Single-family homes receive a special exemption from the proposed regulations because, the hearing report states:

Implementing this standard would impose an undue financial and logistical burden upon homeowners. Properties with one-family dwellings typically maintain higher standards of landscaping and retain more green area.

Imposing expensive mandates on multifamily housing while exempting single-family homes from regulation creates a perverse outcome in which dense, space-efficient housing suffers penalties for being environmentally unfriendly, while low-density homes occupying a small portion of their lot enjoy rewards for "retaining more green area." While the GAR is compatible with high density urbanism, regulations which apply differently to various densities can make some types of housing more expensive, especially small apartment buildings.

The proponents of the New Urbanism, meanwhile, have been working to address stormwater management from an unapologetically pro-urban perspective, recently engaging the EPA in a discussion over existing stormwater standards that may inadvertently penalize density and enourage sprawling development.   Laurence Aurbach's article Dense and Beautiful Stormwater Management discusses these issues in depth, suggesting that planners and regulators accept density as a best management practice for stormwater.

Ultimately, certain landscape elements, green roofs and other innovations may have an important role to play in Washington, but residents deserve to learn more about the long-term costs and benefits of such a large scale, mandatory and relatively untested regulation before adopting it as part of the zoning overhaul.


In old cities, the highest art is often maximizing visible greenery while minimizing GAR. That creates streetscapes of intense greenery at low cost. The tools of this approach are not swales and rain gardens, as useful as these may be, but window boxes, hanging pots, climbing vines and clay urns:

Flickr/Ela2007

Eguisheim, Alsace

Taipei, Taiwan.

Flickr/Joanna_Young

Cagliari, Sardinia.

Tuesday Zoning/Takings Litigation Update

The amount of zoning and takings litigation winding its way through the American judicial system at any given moment is immense, but the first few weeks of the year have yielded some interesting decisions:

• Usurping Legislative Power in Virginia. In Virginia, the state Supreme Court has struck down a longstanding arrangement in Albemarle County in which the planning commission, rather than the Board of Zoning Appeals, had been awarding waivers from the zoning code.  In the case, brought by an aggrieved landowner who also happens to be a University of Virginia law professor, former magistrate judge and current court reporter for the Virginia Supreme Court, the court applied Dillon's rule in concluding that the state had never expressly authorized local planning boards to override zoning ordinances.  Based on the county's reaction, the decision seems to highlight the extent to which local governments are dependent on waivers, variances, zoning modifications and special use permits in administering highly restrictive and inflexible zoning codes (Sinclair v. Cingular).

• Anti-student Zoning in Philadelphia.  The Yorktown neighborhood of Philadelphia, immediately adjacent to Temple University, prevailed upon the city to create a special Yorktown Overlay in which "student housing" would no longer be permitted in its single-family zones, notwithstanding that these zones generally permit at least at least three unrelated persons to live together in a single residence.  Local property owners challenged the overlay after requests to lease to students were denied by the city, alleging that the law deprived them of their property rights under the 5th and 14th amendments. The Zoning Board upheld the overlay on the ground that students "tend to create traffic, parking and noise problems which derogate from the quality of life of families in the neighborhood," and here, the commonwealth court affirms.  This is the first time that I am aware of that a city has taken the bold step of barring a certain class of persons, by name, from a neighborhood (at least since the era of racial zoning).  In the past, towns and neighborhoods, more circumspect about their motives, have generally tinkered with unrelated persons limits to achieve similar ends with respect to student renters.  The owners apparently intend to appeal. (SFH Properties v. Zoning Board of Adjustment of Philadelphia).

• Challenging Findings of "Blight."  Citing property rights principles, the Texas Supreme Court held that an administrative board's finding that a property was a public nuisance did not entitle the city of Dallas to automatically prevail in a takings action brought by the owner of a home demolished by the city. Sadly, it has not been since 1921's Spann v. City of Dallas, a true property rights encomium, that these same principles have appeared in a zoning context. (Dallas v. Stewart). 

Related posts:
Spann v. City of Dallas is not available for a direct link, unfortunately, but I have excerpted portions of it in Ever Since Euclid.

Narrow Streets and NYC: The Problem, or the Solution?

After an earlier post on the spaces in between blocks, I'd like to circle back to consider one of the enduring oddities of New York's particular history with streets, apartments, and the spaces behind them: that being, that the harder the city tried to banish narrow streets, or, more specifically, narrow spaces between buildings, the more they seemd to proliferate.

I've mentioned before that a primary reason that the New York state legislature mandated streets of no less than 50 feet for the city's 1811 plan, and barred the opening of new streets without its consent, was, according to surveyor John Randel Jr., to "[avoid] the frequent error of laying out short, narrow, and crooked streets, with alleys and courts, endangering extensive conflagrations, confined air, unclean streets, &c."

Randel's remarks indicate that he was not only concerned with streets, but with courtyards and other non-street spaces that happened to be narrow or enclosed.  Through a long series of unintended and unforeseen consequences, which I won't repeat here, the result of this focus on avoiding narrow "alleys and courts" was the familiar New York tenement, seen at right in its mid-block "dumbbell" form (source here), in which only one in seven of the rooms opened onto the wide fronting street.  The remainder opened onto a tiny airshaft or looked out over a 10-20' gap between tenements.  Put another way, 11% of the building perimeter faced the street, another 11% faced the rear court, while 78% faced interior light shafts.

The conspicuous failure of the city's dwellings to match the aspirations of the 1879 Tenement House Act eventually resulted in an abandonment of the dumbbell form and the adoption of much larger and more elaborate apartment plans following the Tenement House Act of 1901.  A typical block of "new law" apartments in the Bronx is shown below, governed by a complex set of rules which required courtyards and prescribed minimum widths for these courtyard spaces that ranged from six to 24 feet, with the intent to provide each room with a window opening onto a reasonably large outdoor space:

Again, the city appears to have avoided the opening of any dreaded narrow streets, but if we consider this arrangement of structures closely, it is possible to see how the majority of rooms (around 70%) open onto spaces ranging from 10' to 24' wide – very much within the range Nathan Lewis has defined for his "really narrow streets."  (Confirm on Google Earth if you'd like.)  The network of courts and air shafts even resembles a street network, but no attempt has been made to use it or adapt it for that purpose.

With the new law tenements, New York had come full circle after nearly a century.  The desire to eliminate courts and narrow streets, without an understanding for the reason they had come into being again and again in the traditional cities of the world, had led, unintentionally, to pre-law tenements, old law tenements and at last to the new, where narrow streets, courts and alleys – the very things which the initial 1811 plan had sought to abolish – were effectively re-introduced as the central design feature.

By employing this semi-traditional format of mid-rise apartments on very narrow courts and alleys, and without dedicated parking, but with hypertrophic, automobile-scaled streets, areas built according to "new law" regulations achieved extraordinary densities.  Inwood and Washington Heights, built almost entirely along these lines, have an average density of 130,000 per square mile with very few buildings over six stories.  To put this in perspective, only two other American cities (as of 1990) in the have even one census tract greater than the average density of these neighborhoods.

The failure to let the alleys serve as public rights-of-way, however, saps the vitality of these places by inflating block dimensions and impairing connectivity, while the omnipresent wide automobile thoroughfares detract from the pedestrian experience, as they do elsewhere in the city.  The presence of a few parks is offset by the complete absence of public squares.  A traditional city format, by contrast, addresses these shortcomings while permitting the same intensity of development.

The heyday of the new law tenement was brief, lasting only though the 1920s, after which the ascendant tower-in-the-park design philosophy dispensed with urbanism altogether in a single-minded pursuit of open space, light and air.  Still, the fact that, despite a century's worth of effort against them, courtyards and narrow ways returned as the solution to New York's early 20th century housing problems serves as one illustration of the enduring functional virtues of narrow streets.

Related post: Blocks of New York