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By comparison, New York City's One World Trade Center, now under construction, will rise to a symbolic height of 1776 feet (541 meters), when its pinnacle tower is included. 104 stories will be habitable. Vancouver, increasingly a city of skyscrapers, reportedly has 50 buildings of at least 100 meters (328 feet) in height; building heights are restricted in some places, however, to protect designated view corridors, particularly of mountains and the ocean.

Paris is more like Washington. One of the world's most beautiful and beloved cities, the French capital has generally restricted building heights in the city center in relation to the streets the structures border, with a maximum height of 121 feet (36.8 meters) for new structures. As a result, when one stands on top of the hill in Montmartre, the vista reveals a mid-rise central city, with buildings of six or seven stories. The views of such prominent landmarks as the Notre-Dame cathedral, the golden dome of Les Invalides, the church of St-Eustache, the Louvre and, of course, the Eiffel Tower, are generally unblocked; conversely, when one stands in the Musée d'Orsay on the Left Bank of the Seine, one has a clear view up to Montmartre, with the flamboyant basilica of Sacré-Coeur on top.

There is also the 1970s skyscraper Tour Montparnasse, of course, sticking out like a sore thumb; that's what prompted Parisians to demand a more specific restriction on building heights. And the modern inner suburb of La Défense is filled with skyscrapers, but for the most part Paris is a city of lovely, moderately scaled buildings and beautiful vistas. In central Barcelona, another much-loved city, buildings other than the major cathedrals tend to be between five and ten stories. The same is true in Prague.

All of these cities famous for their mid-rise beauty are now facing their own skyscraper debates, however. In Paris, for example, the city council has recently raised the height limit to 590 feet (180 meters) in certain districts, including the 13th, 15th, and 17th arrondissements to the south and west of the city center. Taller buildings have also been approved in parts of Prague. Is the concept of a mid-rise central city endangered? Should it be?


Opposition to the Building Height Restrictions

A lot of people seem to think so. Strong critics of the DC building height restrictions include, among others, my friend Chris Leinberger, libertarian economist (and suburban Boston dweller) Ed Glaeser, The Economist's Ryan Avent, my fellow Atlantic Cities writer Emily Badger, prolific blogger Matt Yglesias, and one of my favorite urban thinkers, DC architect and Washington Post columnist Roger Lewis. The popular local urban affairs blog Greater Greater Washington has run several features about the restrictions, including editor David Alpert's "Should the Height Limit Change?" earlier this month. The (mostly) fair, presenting-all-sides (against the restrictions, for them, various in-between schemes) article had drawn 119 comments as of this writing, very few of them in support of current law.

The arguments against the height limit boil down to these, more or less:

• Under current law, DC cannot grow because it is running out of room.


• By restricting the supply of housing, the height limit is making DC unaffordable.


• Urban density creates better places and a better environment and should not be restricted.


• The height limit leads to mediocre architecture and city design.

Here's why I disagree:

• Actually, DC can grow under current law. In 1950, with the height restrictions fully in effect, the city's population was 802,178. In 2011, its estimated population was 617,996. The truth is that we were a "shrinking city" until about a decade ago, and we are nowhere near full capacity today. Maybe the reason developers say we "can't grow" is because we may be running out of large, undeveloped sites suitable for mega-projects. Personally, I don't see why that's a bad thing: I think it would be better for the city (if not for large developers) to add new buildings in a more incremental, fine-grained way on smaller parcels as their current uses go out of service. (A more analytical presentation of the facts supporting DC's room to grow under current law may be found in testimony earlier this year to a Congressional subcommittee, presented by the Committee of 100 on the Federal City.)


• A lot of other things are going well under current law, too. As Derek Thompson wrote in The Atlantic, Washington is the richest and best-educated metro area in America, leading the nation in economic confidence. Far from being "provincial," Washington has become one of the most cosmopolitan cities in the country, attracting visitors from all over the world. It is also a long way from being "low-density": It may not be as dense as New York, San Francisco or Boston, but Washington is significantly denser than many large US cities with skyscrapers, including Baltimore, Oakland, Seattle, Portland, Denver and San Diego. If you're looking for an example of a low-density city, try Kansas City (1,630.4 persons per square mile (629.5 persons per square kilometer) of land area, as compared to Washington's 10,065), Phoenix (2,797 persons per square mile), Dallas (3,518 persons per square mile), or Atlanta (4,020 persons per square mile), all of which have skyscrapers.


• Building height has little to do with affordability. The argument that a limit on building height restricts housing supply and thus leads to higher prices is essentially the same argument made against Portland's urban growth boundary. In both cases, it's hogwash: if affordability were closely related to building height and density, New York City and San Francisco would be the two most affordable big cities in America.


• Just because urban density is good doesn't mean that more is always better. I couldn't agree more with the proposition that sprawl has been horrible for America and that generally increasing the density of our built environment — especially above what we built in the second half of the 20th century — is essential to a more sustainable future. I've staked my career on it. But the key is to increase average density all across a metro area so that the region's footprint doesn't expand; parts of the region that are already relatively dense, such as downtown Washington, are fine as they are.

This is supported by research: the environmental benefits of increasing density — including lower rates of driving and stormwater runoff (when measured in the watershed as a whole) — are dramatic indeed as density increases from large-lot sprawl to village-style densities of 20 units per acre (49 units per hectare) or so. But, above a certain point, the environmental benefits of incremental increases in density taper off. There is little additional benefit to these environmental indicators, for example, as density increases beyond about 60 homes per acre (148 homes per hectare), as one might find in a three- or four-story apartment building. Indeed, there is even some evidence that taller buildings create negative environmental impact per increment of additional space compared to building heights typically found in central Washington or Paris. Taller buildings need stronger support materials that require greater amounts of energy to produce.

• In any event, denser doesn't necessarily mean taller. These numbers may surprise you: Barcelona is denser than New York City, housing 41,000 people per square mile (15,830 people per square meter) compared to New York's 27,000 (10,425 people per square meter). Barcelona's beautiful and thriving, mid-rise central district L'Eixample is denser than Manhattan, at 92,000 people per square mile (35,500 people per square meter) compared to Manhattan's 71,000 (27,400 people per square meter). It does not have buildings taller than Washington's. In DC, we could increase density substantially by incrementally converting many aging one- and two-story buildings in commercial and mixed-use districts to a still-human three to five stories.


• Architectural mediocrity has nothing to do with building height restrictions. I'll grant that Washington, like just about every other American city, has some lousy commercial architecture. (It also has some very good newer commercial architecture, in my opinion.) And, when buildings are mediocre, their shortcomings may be magnified by a uniform height. But, my goodness, how can one say that lifting the building height restrictions would help? Maybe it's a matter of taste, but to my eyes the unrestricted high-rise architecture of the denser suburban centers near our area's Metro stations — probably a decent approximation of what we might get downtown without the height limit — is worse, ranging from boring to awful. My favorite of the area's newer, transit-accessible suburban projects is the more moderately scaled Bethesda Row, a lively, mixed-use development built well within the parameters of the DC limitations.


• Taller buildings can have a negative effect on the quality of light and tree cover. Paris is called la ville lumiére (city of light) for a reason. Its wide boulevards and mid-rise buildings allow much more light into the city center than do the frequently shaded skyscraper streets of, say, Manhattan. The same is true in Washington. The benefits are partially medical: sun and bright daylight stimulate the brain's production of serotonin, which enhances mood and staves off depression. Research shows that the brighter the daylight, the brighter the spirit; conversely, limited exposure to sun and bright daylight is associated with symptoms of depression.

On a related topic, the amount and quality of light have an effect on the natural environment, too. My NRDC colleague Geoff, who advocates increased density in his own neighborhood, says he nonetheless supports DC's height limits "because of the trees." He may be on to something: New York City's tree cover is at 20.9 percent, below the national average of 29.9 percent (based on a 20-city study by researchers from the US Forest Service) and far below the 40 percent recommended by the conservation organization American Forests. Washington's tree cover is 35 percent. While surely there are many contributing factors, the two cities have very similar climates and one would not expect such a large disparity. Light is likely one of the reasons.

• The importance of Washington's vistas and distinctiveness should not be underestimated. This observation may be somewhat subjective, but I believe one can see farther and better in DC than in other large American cities, and this distinguishes Washington from other places. It's partially the views of the iconic national monuments, of course: one can see the Washington Monument from all over the city, and the view from the Virginia side of the Potomac River into the city is truly breathtaking. One of the places sometimes cited as a candidate for taller buildings is the Southwest Washington waterfront; if they were allowed there, some of those views as we now know them (from, say, the Mount Vernon bike trail) could be significantly compromised.

But this is critical: it isn't just the views of the monuments: in Washington there are many places where one can see other notable landmarks such as Washington National Cathedral, the Shrine of the Immaculate Conception, the spires of Georgetown University's Healy Building, or the Potomac River itself, just to name a few. It's also the feel of the neighborhoods: even without long-range vistas, neighborhoods like the wonderful Dupont Circle would feel totally different surrounded by taller buildings. This is a big part of what makes DC special, and I wouldn't mess with it.

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Kaid Benfield is a cofounder of the LEED for Neighborhood Development rating system; cofounder of the Smart Growth America coalition; author of Once There Were Greenfields, Solving Sprawl, Smart Growth In a Changing World, and Green Community; and was voted one of the "top urban thinkers" in a 2009 poll at Planetizen.

This article originally appeared as "Why I support the DC building height restrictions" by Kaid Benfield, copyright © 2010, and is published with permission of the Natural Resources Defense Council.