CC image from Alan Grinberg

The first thing crossing my mind when reading Vishann Chakrabarti’s piece in Design Observer (Building Hyperdensity and Civic Delight) was: what the hell is ‘hyperdensity?’ Thankfully, Chakrabarti answers that question in the first paragraph: “density sufficient to support subways.”

The second thing to cross my mind was why he would frame a reasonable kind of urbanism – transit-supportive density – in such extreme terms? Chakrabarti is a principal at SHoP Architects and a professor at Columbia. Hearing someone in that position praise the very real benefits of density isn’t surprising, though the framing of the issue as ‘hyper’-anything seems naive in the face of neighborhood opposition to even minor changes like the allowance of accessory dwelling units.

Contrast Chakrabarti’s position to that of Brent Toderian. Toderian, formerly the chief planner in Vancouver, BC, is a veteran of many contentious civic battles over development and density. His calling card is to focus on mitigating any possible downside of density, re-branding the ideal as ‘density done well.’ Leaving aside any substantive differences between Toderian and Chakrabarti, the difference in framing is significant. Both praise the benefits of density for an urban economy, for climate change, and for city life; both agree that dense environments demand good design to address the challenges that density can present. Yet, Toderian emphasizes that it can be ‘done well’ (implying that it currently isn’t done well) while Chakrabarti emphasizes the need for more density (implying that we don’t currently have – or allow – enough of it).

Chakrabarti isn’t satisfied with the small-scale focus from current planners, and embraces the general focus of the econourbanists:

Today the global economy demands that we embrace large buildings not just for housing but also for many modern office functions; yet many planning professionals remain fixated on smaller-scale development. They tend to ignore that height limitations have held back the Parisian economy in comparison to the forward-looking redevelopment of London, both at Canary Wharf and within its city center, which is now marked by a series of glistening and respectful new towers by Norman Foster, Richard Rogers and Renzo Piano. There is, in fact, a marked correlation between those European cities that have allowed skyscrapers and those that have successful economies.

Chakrabarti also mentions the challenges of building denser cities in today’s regulatory environment of zoning codes and lengthy reviews, risk-aversion from incumbent residents and landowners, and the feasibility of adding new infill development into established neighborhoods without fundamentally altering their character.

Perhaps the single most compelling reason to act is the growing challenges of affordability. This Wall Street Journal article highlights the challenges in New York, quoting Professor Chakrabarti extensively:

In the coming decades, New York could confront a problem many cities would love to have: too many people and nowhere to put them.

The city is expected to add one million more residents by 2040, but there likely won’t be room for hundreds of thousands of them unless a small city of new housing is built, according to a report by a Columbia University think tank.

“What surprised me most was the scale of the problem,” Mr. Chakrabarti said. “It’s a clarion call that we don’t have enough housing.”

At the same time, plenty of other publications about affordability challenges in cities around the world do not even mention the restrictions on and challenges to add housing supply.  At the same time, the fact that many American cities used to have more people residing in the same area will lead them to believe that the city can accomodate more people without exanding the city’s building stock. The reality is that those older population figures included larger household sizes and fail to account for housing stock lost to commercial development from expanding downtowns. Payton Chung looks into these claims for DC:

These conditions were common in District homes at the time. The 1950 census found 14.1% of the District’s 224,142 occupied housing units to be overcrowded (with >1 person per room). By 2011, that figure had fallen two-thirds, to 4.7% (an increase from 3.3% in 2008) — a figure lower than the 5.3% of homes that were extremely overcrowded (>1.5 occupants per room) in 1950.

On average, every apartment and house in DC had one more person living inside — households were 50.2% larger! In 1950, 3.2 people occupied each dwelling unit (for non-whites, it was 4.0). In 2007-2011, the number of persons per household had fallen to 2.13, while the number of housing units had grown to 298,902.

As the city gets reacquainted with the notion of population growth, and begins to plan for a much larger population within the same boundaries, we’ll have to have a realistic conversation about household sizes and housing production. A change of just 0.09 persons per household means the difference between planning for 103,860 units or 140,515 units.* In either case, though, that is one heck of a lot of construction for a city of 68 square miles, of which 10.5 are parks and 7 are underwater. It works out to 2,000-3,000 additional units per square mile — as simple as building a platform and plop 5 DUA suburbia across it, or as complicated as infilling a contentious, built-up city. (More the latter than the former, I suspect.)

That problem can’t be solved with just a few new mega-development sites absorbing all of the demand for urban growth. It requires existing neighborhoods to help absorb some of that demand.

At the same time, Chakrabarti is well aware of the regulatory challenges to merely allowing the market to add density to an already-established city:

At Columbia University, my students and I have been working on a concept I call “cap and trade zoning,” which would allow the free flow of air rights within an urban district, with an understanding that the overall amount of developable area would be capped in relation to proximity to mass transit. This would result in hyperdensity, to be sure, but would also create a “high-low” city of diverse heights, uses and ages. This concept would strengthen small businesses by permitting owners to sell their air rights, while allowing development to occur on nearby lots. Critics may argue that this approach would result in unpredictable development with varying building scales, to which I would reply “Hip hip hooray!” Much of what passes as good planning today is known as “contextual zoning,” a mechanism through which new architecture is tamed into mediocrity by mimicking a false understanding of the scale and aesthetics of existing neighborhoods. Too often this process allows a lowest-common-denominator mentality to trump the wonders of the unpredictable city. Half a century ago, in The Death and Life of Great American Cities, Jane Jacobs relentlessly critiqued the planner’s urge for control; her critique is no less pertinent today.

The concept is good, but what remains to be seen is if it could pass the political test – and if it could adjust the regulatory process (not just the regulatory content) that governs urban development decision-making. Perhaps the first test of the political viability of ‘hyperdensity’ will be if the name helps advance the needed regulatory reforms.