As noted in my previous post, there is no question that sustainable land use requires, among other things, neighborhood density.  Smart growth based on walkable neighborhoods, transportation choices, nearby amenities and the accommodation of an increasingly diverse society is the only way we can limit per-capita impacts, and thus total impacts, to a manageable level.

But, as I also wrote then, we must be honest with ourselves if we are to get this right:  Environmental impacts will occur with development; to limit them, we must concentrate them, and this can mean increasing them in some places.  This is what I call "the environmental paradox of smart growth."  Only if we understand the paradox can we address it.  Only if we address it can we really create better places in which to live, work, and play – and surely that, not just lowering pollution numbers, must be our real goal.

This is the second of two posts I am writing on the subject, in conjunction with a presentation I am giving at the annual meeting of the American Planning Association.  Part one appeared last Friday.

To mitigate and compensate for the environmental and community impacts that can accompany compact development if we do not plan carefully - such as increased local emissions and traffic congestion, local stormwater runoff, and limited green space, among others - I believe we must aspire to not just good places but great ones.  As I wrote before, we should build to appropriate scale, in many cases with moderation; we should include green infrastructure; we should provide an array of transportation choices; and we should provide parks and civic amenities. 

I may not be able to sell a high-rise canyon to the public as an example of smart growth, but fortunately there are models that we can hold up as good ambassadors for our cause and that we can emulate in future development.  Indeed, I think it is important that we settle for no less.  Here are images of 14 such places, for which I thank their developers and architects as I congratulate them on their excellent work.  (Regular readers will have seen some of these in other contexts.)  Enjoy, and spread the word:

Left, Sacramento's Metro Square includes 20 single-family homes per acre. Right, Vancouver's Millennium Water (formerly the Olympic Village) will include 148 homes per acre.

Left, the small-town infill project Third Street Cottages in Langley, Washington, comprises 12 homes per acre.  Right, Benedict Commons, workforce housing in Aspen, Colorado, looks like a collection of two- and three-story buildings; it's actually a single building containing a surprising 78 homes per acre.

Left, Rockville, Maryland's transit-oriented Twinbrook Station has earned a LEED-ND gold level certification; it includes a central green square and still provides 61 homes per acre gross.*  Right, Seattle's award-winning, mixed-income High Point sports the country's most advanced green stormwater management while still providing 12.5 homes per acre gross.*  (High Point is also shown in the aerial photo near the beginning of this post.)

Left, Atlanta's Glenwood Park provides approximately 14 homes per acre gross.*  Right, Fukuoka, Japan's amazingly green ACROS building provides distinction, beauty, and vegetation to its city despite offering 1.4 million square feet of floor space.

Left, this green-roofed, four-story building in Vancouver includes 39 homes per acre along with 212,000 square feet of retail space underneath the green.  Right, Denver's acclaimed Highlands' Garden Village clocks in at 22 homes per acre.

Left, the 50,212-square-foot embassy of Finland in Washington, DC, is the world's first LEED-certified embassy; everything about the building's beautiful facade says "green."  Right, Berlin's wonderful Sony Center provides a dense floor-area ratio of 5.0 along with 1.4 million square feet of downtown space, while also contributing wonderful public amenities. 

Left, Via Verde in the South Bronx provides an impressive amount of urban green to its community while housing 45 homes per acre gross.*  Right, Burien, Washington's Burien Town Square includes a common green beside condos that come in at 83 homes per acre.

Finally, a reprise of sorts with another view of Denver's Highlands' Garden Village, showing its urban garden in the foreground.  As noted, HGV provides 22 homes per acre.  It also provides a commercial area, civic buildings, lots of green space, homes for seniors, and affordable housing, and is one of our cause's better ambassadors.

* "Gross":  In several cases, I did not have convenient access to precise measurement of residential units per buildable acre, excluding commercially dedicated land.  For these I simply took the total number of homes and divided by the development's total number of acres, for a quick calculation of gross density.  These numbers are inherently conservative, since excluding commercial or non-buildable land from the calculation would yield higher density results.

Kaid Benfield writes (almost) daily about community, development, and the environment.  For more posts, see his blog's home page. 

There is no question that sustainable land use requires, among other things, neighborhood density.  Indeed, I have basically staked my career on the proposition that we must increase the average density of our new (and, in some cases, existing) built environment in the US if we are to achieve anything near sustainability as we absorb more growth.  Nothing has been worse for our environment than sprawl.  Smart growth based on walkable neighborhoods, transportation choices, nearby amenities and the accommodation of an increasingly diverse society – more urbanism, if you will – is the only way we can limit per-capita impacts, and thus total impacts, to a manageable level.

But we also must be honest with ourselves about something, if we are to get this right:  Environmental impacts will occur with development; to limit them, we must concentrate them, and this can mean increasing them in some places.  This is what I call the environmental paradox of smart growth.  Only if we understand the paradox can we address it.  Only if we address it can we really create better places in which to live, work, and play – and surely that, not just lowering pollution numbers, must be our real goal.

This is the first of two posts I am writing on the subject, in conjunction with a presentation I am giving at the annual meeting of the American Planning Association.  Part two will appear on Monday.

The density imperative

This blog and the sources I cite within it are replete with data showing that increased neighborhood density - as measured by residences per acre, or square feet of nonresidential space per acre - reduces environmental impacts from driving rates and associated emissions, to stormwater runoff, to intrusions on farmland, wildlife habitat, and scenic and cultural resources.  There is perhaps no better or more thorough illustration of this than the massive Housing + Transportation Affordability Index recently expanded and published by the Center for Neighborhood Technology (CNT).  It shows in 337 metro regions across the country how driving rates, related carbon emissions, and transportation costs are uniformly lower in denser neighborhoods. 

Other studies show that denser neighborhoods help protect watersheds.  EPA research, for example, proves that developing a thousand homes on a 10,000-acre watershed at an average density of eight homes per acre will reduce runoff by more than two-thirds compared to a density of one home per acre, because the more compact development requires less runoff-inducing street and surface parking infrastructure per household.  Building more densely also saves resource lands: the deservedly acclaimed Sacramento Blueprint, by directing growth in that region to a more orderly and compact pattern over a 45-year period, would conserve 357 square miles of land, including 64 square miles of farmland – while keeping 64 percent of the region’s households in single-family, detached homes.  Still other studies show that density improves public health by facilitating walking. 

There is simply no valid solution to global warming, to food security, to ecological conservation – to say nothing about redressing urban disinvestment – without using smart, compact growth to replace sprawl.  I happen to think it also creates better environments for people to live in, but I suppose that is to an extent a matter of taste.

But density can increase local impacts

Unfortunately, all these benefits do not necessarily mean that that the NIMBY (not in my back yard) crowd is being irrational when they oppose dense development.  Quite the contrary:  they intuitively understand that density – especially in the forms in which they have seen it in recent years – can, if not very carefully designed and managed, bring harm to the neighborhood environment. 

Consider the GIS maps above of metro Boston and metro Seattle.  The Boston map on the left shows that, under a smart-growth planning scenario that would direct more growth and building to already-developed areas (and that I likely would support), it is precisely those areas that are increasing in density that will experience increased (if not necessarily by very much) traffic congestion; what it doesn’t show is that some of those areas already have significant traffic congestion.  The Seattle map on the right shows that the areas that are the most dense have the most per-acre impervious surface, and thus will generate the most on-site stormwater runoff during rainfall events, which are not infrequent in Seattle.  (A per-capita map of impervious surface would show that dense areas have the lowest rates by that measure, but that doesn’t necessarily help the urban watershed.)

The maps just above show the pattern of transportation-related emissions: carbon dioxide in metro Washington, DC on the left, and volatile organic compounds in metro Hamilton, Ontario on the right.  Both show the greatest local concentrations in areas of density.  (One might argue that the spatial pattern of CO2 doesn't matter, because the main threat of CO2 is to the planet, not individuals.  But the emissions pattern shown for CO2 is not a bad proxy for other driving-related emissions that are more troublesome to individuals, such as nitrogen oxides.)

Impacts on parks and green space

But perhaps no impact of poorly planned neighborhood density is more visible than the loss of green space.  Look below at the satellite image of the area around the Ballston Metro station in Arlington, Virginia.  By all accounts, Ballston is part of a tremendous smart-growth success story when it comes to transportation performance.  The corridor in which it sits has absorbed a huge amount of growth with only minimal increases in auto traffic, because so much of the new development is convenient to the Metro.  That growth has also been a big asset to Arlington’s tax base.  From 1980 to 2005, the 260-acre Ballston station planning area added 6584 new homes, 6.37 billion square feet of office space, and 958,000 square feet of retail.  As of 2000, it was home to nearly 11,000 residents (not counting jobs), and I would wager that the population is up to at least 15,000 now.

But almost no new park space came with the influx of new development.  Working with my friend Peter Harnik, who heads the Center for City Park Excellence at the Trust for Public Land, we found about two and a half acres, some of which is privately owned and under some access restrictions, of pre-existing and new parkland within the planning area, with another half-acre or so on the way.  You can see the markings of their locations on the image. 

These pocket parks within the station area add up to about 0.27 acres per thousand people, based on the 2000 population (which is almost certainly lower than the current population).  Peter’s brand-new book, Urban Green, reports that most American cities provide between 5 and 35 acres per thousand, or upwards from 20 times what Ballston provides.  (There are some athletic fields outside the planning area boundary to the northeast, but to experience a genuine park of size for urban respite, a Ballston resident would have to walk over a mile, traversing a freeway overpass.) 

Ballston is basically a high-rise canyon.  I can advocate it to planners, because of its outstanding transportation performance.  But I’m in the business of selling smart growth to the public at large, and I have a very hard time selling the likes of this type of development to the public, other than the most committed urbanites.

We can do better than this, and must

I believe we will never succeed in accomplishing the many environmental and community goals of smart growth without earning the broad support of the public, both on a national level and within individual communities.  And I submit that we can do much, much better.  I’ve argued before (see also here) that smart growth and environmental advocates have been insufficiently ambitious in advocating the better, more compact communities that we all know we must have. 

I should add that I have come to this view only over time.  For years, I felt that density, location, and transit access were the keys to smart growth, and the more of them, the better, without thinking too much about nuances of community and design.  I was wrong about that and, sadly, I fear much of the smart growth movement remains stuck where I used to be.  If the legacy of our advocacy is to be a better environment in which to live, we muct become more sophisticated and demanding in what we advocate, whether the debate of the day is about transportation policy, sprawl, reinvestment, or something else.

Here are at least four ways we can make the neighborhood density that is so essential to smart growth more appealing and green:

• Build appropriate scale and recognize the benefits of incremental density.  We don’t need to convert Middle America to the density of Hong Kong, or even Ballston in most cases, to improve environmental performance.  Sometimes downtown-type density will be appropriate, but the many graphs I have seen plotting the relationship between neighborhood density and per capita driving rates (and emissions) all show that the greatest increments in performance improvement come at the lower end of the scale.  One of CNT’s graphs, for example, indicates that driving is cut by more than half as one moves from large-lot sprawl (one-acre and half-acre lots) to smaller-lot single family homes (around 10 units per acre).  Beyond that, we can get further improvement, but only at a much more incremental rate.  The graph begins to level out around 20 homes per acre.  We accept incremental change much more easily than drastic change.  
• Incorporate green infrastructure for stormwater mitigation and livability benefits.  Rachel Sohmer of our smart growth staff and many colleagues on NRDC’s water quality staff, along with yours truly, have written extensively about green approaches to stormwater management.  Seattle, in particular, has a terrific set of guidelines for incorporating vegetation, green roofs, drainage, pervious surfaces and other low-impact development techniques that allow the urban watershed to thrive (and, in many cases, recover) with density.  Most of these also have the benefit of bringing more nature into the urban landscape, with a range of additional benefits.  But green benefits seldom happen by accident.  We have to design and build them into our development and infrastructure. 

The density advocates par excellence at CNT have a calculator on the organization’s web site showing how much stormwater one can capture (and thus how much runoff one can prevent) under various scenarios.  For example, their pre-loaded scenario “would decrease the site's impermeable area by 42.9% and capture 300% of the runoff volume required. Compared to conventional approaches, the green practices in this scenario will decrease the total life-cycle construction and maintenance costs by 8% (in net present value).”

• Make sure that development offers a rich array of transportation choices.  Transportation efficiency is critical to the goals of smart growth, but it is also a key to minimizing the congestion impacts of density.  Some important elements include making sure that the site has a variety of destinations within walking distance, such as shops, services, and amenities; an inviting pedestrian environment that includes sidewalks, street trees, and attractive street frontages (LEED-ND’s walkable streets standards provide great guidance); well-connected streets without dead ends; and, of course, frequent and convenient public transportation.
• Build parks and civic amenities into the density.  Ballston is hardly the only neighborhood experiencing substantial development without adequate provision for parks and green space.  While this may be somewhat easier to do when there is a master developer controlling a larger development, good planning can build amenities into the requirements for parcel-by-parcel development, too.  My friend David Dixon, a relentless density advocate, often speaks of the “density dividend” that can bring civic amenities into a community.  These can and in many cases should include libraries, schools, and community centers, too.

I believe the environmental paradox of smart growth(that compact development can increase as well as reduce impacts) requires that we be thoughtful about our approaches to increased urbanism and make sure that it brings genuine benefits to communities.  The fears that surround new development, especially dense development, are understandable and, in some cases, well founded.  Heaven knows we have given folks enough crappy projects over the last fifty years to stoke those fears for a long, long time.  I would rather address those fears than wish them away.

Simply put, we need more, better, greener ambassadors if we want to make smart growth and urbanism the norm rather than the exception.

Next, on Monday: a gallery of beautiful and innovative density.

Kaid Benfield writes (almost) daily about community, development, and the environment.  For more posts, see his blog's home page. 

The city planners of Anchorage, Alaska, are attempting to bring that city’s land-use regulations into the 21st century.  In particular, they are proposing a variation on form-based zoning that would encourage mixed uses, orientation of development to the street, and pedestrian- and people-friendly building design.  This has been a massive undertaking, in the works for the better part of a decade.  And it is running into opposition.

Note: Today’s post is co-authored with my good friend Lee Epstein, a seasoned and very policy-savvy environmental lawyer and land-use planner.

Longtime Anchorage planning director Tom Nelson articulated the rationale in 2006 in the Alaska Business Monthly:

“Like most cities, Anchorage's land-use regulations have encouraged single-use districts, and reliance on a single mode of transportation to connect them--the automobile. This has led to a more sprawling land-use pattern and greater consumption of energy resources than would otherwise be the case . . . as one looks ahead, there is a need to create other viable, attractive and less energy-consumptive choices for transportation--be it walking, biking or transit--as well as to shorten distances to destinations . . .

“Mixed-use developments, winter-city design, energy-conserving buildings and transportation systems, creation of public spaces and retention of important open spaces are all increasing in usage. These trends in land development coincide with many of the solutions proposed in response to the changing economic circumstances and community aspirations in Anchorage. As developers, residents and local officials see the benefits of these attributes, Anchorage's land-use code needs to change in order to help accommodate and facilitate them.”

Writing last week in the Anchorage Daily News about changes the new code would bring to the commercial sector of Anchorage development, Rosemary Shinohara reports that “under the proposed new rules, a local builder no longer could put a windowless, blank side of a commercial building next to the street” but, instead, would be required to choose from a menu of options within each of three major design categories:

• Windows, entrances and the building's orientation in reference to the sidewalk and street. Opening to the street rather than just to offstreet parking lots helps walkability, visual appeal, and a sense of community.
• Building design. Shinohara: "Examples of choices are setting an upper story back from the lower stories; building a plaza; adding a second color, texture or material to the front of the building; or creating recesses or projections so the facade is not just a flat surface."
• Northern climate considerations. The code's menu includes entrances protected from the weather, sheltered or ice-free walkways, sunlit atriums, and balconies or marquees that project out over a sidewalk or entrance, providing cover.

Seems sensible, no?  But Shinohara also writes that “a group called the Building Owners and Managers Association has started a petition drive to get the city to kill the massive, seven-year-long, 14-chapter modernization of local zoning laws, of which commercial design standards are part. They want the city to stay with existing code,” which as far as we can tell has pretty much allowed commercial developers to do whatever they want.  This is, after all, a notoriously independent part of the country that doesn’t warm to government involvement very easily (except, um, for those timber, oil, and gas subsidies, but that’s another matter). 

The proposed code is scheduled to come before the city’s decision-making Assembly for adoption this spring.

Anchorage’s circumstances raise some important issues about how best to improve urban landscapes and urban livability – sometimes in the face of libertarian attitudes about government.  More expansively, how best can citizens and their governments, organized by the consent of the governed into a constitutional system aimed at enforcing the responsibilities of citizenship toward the common good, better attain those ends?  That’s a mouthful, but the query is aimed at those who will always say, “Not me, buddy.  I know what’s best for me.  And unless you’re calling to rescue me from my burning building, stay out of my hair, OK?”  Such a response is too often engendered whenever new local requirements are proposed, whether necessary to clean up a community’s rivers and streams, keep children out of danger or, heaven forbid, keep truly ugly buildings from proliferating like dandelions in the spring.

But let’s face it:  Blank walls running along a city street are ugly, and they’re even dangerous.  They allow for no “eyes on the street,” crucial (by all professional law enforcement accounts) for keeping streets safe.  And they’re the architectural equivalent of presenting your backside to the rest of the world – all the time.  Lovely.

But how do you “legislate” them away?  How can a local government best achieve the legitimate aims of enhancing public safety and securing for the benefit of all citizens a more functional, efficient and, yes, attractive community?  After all, you can’t pass a law that requires “good taste,” whatever that is.  (At least that’s the apparent complaint of some of our architect friends, who fear some draconian curb on their creativity.  C’mon.  Apart from the fact that form-based codes are themselves the work of gifted architects, maybe it’s that insistence on sculptural freedom and “creative” architecture that sometimes gets us into this fix in the first place.  But don’t get us started.)

Regardless of what some might think, most of us do live in communities.  And the constitution says that communities have the right – and the responsibility – to provide for the public good, and the general health, safety and welfare of all their citizens.  Sometimes that is going to mean that, after a lot of open consideration, an ordinance will be passed that requires citizens to pony up to the mutual responsibilities bar: ‘We [insert name of community] pledge to keep you safe and keep our community livable and economically energetic, while you [insert name of citizen and business alike] pledge to uphold certain standards of behavior and action.’

That’s how we see attempts such as those that Anchorage is making, or similar ones elsewhere, to try to eploy reasonable new zoning standards to improve a city’s image and look, its functionality, walkability, and environmental quality.   We elect representatives to make these decisions, and if the process is an honest and open one, we should honor our subsequent responsibilities as citizens.

With respect to Anchorage’s proposed new zoning, no, good taste cannot be legislated.  But certain minimum standards and principles can be articulated that express qualitatively or quantitatively how a community wishes to present its face to the world – standards relative to proportionality, bulk and height, scale, location on a street, pedestrian functionality and yes, even how the street-level façade should function.  A city might achieve this with a variety or menu of choices, or provide some incentives and disincentives to property owners and developers.  (For an interesting presentation showing the issues Anchorage is trying to address, and some modest improvements the new code would encourage, go here.  Most of the images in this post are from that presentation.) 

The bottom line is that local communities can and should take on, through mechanisms like zoning, how they look, how they function, or how green they become – because the alternative is to succumb to the lowest common denominator, and (as Ian McHarg once said about failing to achieve environmental quality through good planning and zoning) to let the devil take the hindmost.        

Kaid Benfield writes (almost) daily about community, development, and the environment.  For more posts, see his blog's home page. 

As noted in DOT’s press release accompanying the announcement, “The TIGER (Transportation Investment Generating Economic Recovery) Discretionary Grant Program was included in the Recovery Act to spur a national competition for innovative, multi-modal and multi-jurisdictional transportation projects that promise significant economic and environmental benefits to an entire metropolitan area, a region or the nation.” 

About half the money will go to transit and rail projects, including $83 million to fund the first phase of the long-anticipated “new Penn Station” in Manhattan.  The new facility will occupy the city’s huge Farley post office building across Eighth Avenue from the current Penn Station and Madison Square Garden.  It will be named for New York’s late Senator Daniel Patrick Moynihan, who championed the project while he was still alive.  Moynihan also was the principal author of the landmark 1991 federal transportation legislation that for the first time opened federal transportation funding to community and environmental projects.

What a great and fitting tribute to a giant among legislators.  And what remarkable evidence of this administration’s much-appreciated commitment to efficient, people-oriented transportation.

The group Friends of Moynihan Station hailed the announcement, which completes the funding necessary for Phase One of the project, which will include new entrances to the current, underground Penn Station from the Farley building, major improvements to passenger and visitor concourses, and new escalators, elevators and stairs to the train platforms.  Construction can begin late this year.  Phase Two will include, among other major improvements, an iconic, open train hall in the Farley Building.  Penn Station is the nation’s busiest transportation facility, handling over 600,000 passengers daily.

Those of us who use it, and that includes me when I travel to New York several times each year, know that the current Penn Station leaves a lot to be desired, to put it mildly.  Unlike wonderful stations in DC, Philadelphia, Paris, Berlin, and London, just to name a few, Penn station is cramped, claustrophobic, and completely devoid of natural light.  While there have been some heroic attempts at improving the place over the last 10-15 years, it is not somewhere you ever want to be if you don’t have to.  It doesn’t come remotely close to Grand Central, Manhattan’s iconic station on the East Side.

And that’s a shame, because Penn Station once was itself grand and inspiring (see photo of its interior, below).  It was demolished to make way for the current facility as a result of a litigated decision that was lost by the old station’s proponents but nonetheless galvanized the preservation movement in New York and elsewhere.

When the new project is finished, intercity passengers using Amtrak will be shifted to the Farley building, and local and regional commuters using New Jersey Transit and the Long Island Railroad will be given more space in what is now the current facility.  While there is no doubt that the major upgrade to Eighth Avenue will spur additional redevelopment near the new station, the project will focus on its transportation purpose.  The New York Times saluted this decision in a recent editorial, noting that given earlier talk of an elaborate mix of major shopping, housing, and sports facilities in the project, its focus – and, given the recession, perhaps even the whole idea - was in danger of being lost.  New York’s senior senator Chuck Schumer has been credited with reframing the project to place the emphasis on the station itself, and with helping the project seek stimulus funding.

I had the pleasure of hearing Pat Moynihan speak a couple of years before his death, and it was one of the most intellectually impressive speeches by a politician that I have ever heard.  I was sitting at a large dinner with a seasoned lobbyist from the National Trust, who leaned over and said, “There will never be another like him.”  But now at least there will be a legacy.

Here’s a short video – now somewhat dated (Eliot Spitzer was New York’s governor at the time) – that was produced by the Municipal Art Society of New York, explaining the genesis of Moynihan Station and its proponents’ goals:

Principles for a Great New Penn Station from MAS on Vimeo.

Kaid Benfield writes (almost) daily about community, development, and the environment.  For more posts, see his blog's home page.