The Hidden Potential of Sustainable Neighborhoods

Lessons from Low-Carbon Communities

Harrison Fraker

• Editorial: Island Press
• Año: 2013
• ISBN:
  9781610914093
• Categoría: Architecture
• Categoría: Architecture General

How do you achieve effective low-carbon design beyond the building level? How do you create a community that is both livable and sustainable? More importantly, how do you know if you have succeeded? Harrison Fraker goes beyond abstract principles to provide a clear, in-depth evaluation of four first generation low-carbon neighborhoods in Europe, and shows how those lessons can be applied to the U.S. Using concrete performance data to gauge successes and failures, he presents a holistic model based on best practices.The four case studies are: Bo01 and Hammarby in Sweden, and Kronsberg and Vauban in Germany. Each was built deliberately to conserve resources: all are mixed-used, contain at least 1, 000 units, and have aggressive goals for energy and water efficiency, recycling, and waste treatment.For each case study, Fraker explores the community's development process andgoals and objectives as they relate to urban form, transportation, green space, energy, water and waste systems, and a social agenda. For each model, he looks at overall performance and lessons learned.Later chapters compare the different strategies employed by the case-study communities and develop a comprehensive model of sustainability, looking specifically at how these lessons can be employed in the United States, with a focus on retrofitting existing communities. This whole-systems approach promises not only a smaller carbon footprint, but an enriched form of urban living. The Hidden Potential of Sustainable Neighborhoods will be especially useful for urban designers, architects, landscape architects, land use planners, local policymakers and NGOs, citizen activists, students of urban design, planning, architecture, and landscape architecture.

Figure 1.1. Lower Manhattan blackout caused by Hurricane Sandy. (Photograph by Reeve Jolliffe / Gas Tower Studio.)

1. Introduction

In our media-saturated culture it can be argued that, until recently, the threat of climate change seems to have been overexposed. People have been numbed by the repetition of potential threats that seem complex, distant, and hard to personalize. All of this is changing as people experience the devastation of extreme weather events, especially with the impacts of Hurricane Sandy and the hundred-year droughts in the Midwest. Climate change is no longer about reports of the Intergovernmental Panel on Climate Change or the efficacy of climate science. Its consequences are real and palpable. As a result, there is a renewed sense of urgency about how to respond and an opportunity, however brief, to ask fundamental questions about business as usual in the way we build, operate, and maintain our cities. How well can cities defend against and recover from severe climate disruptions?

There is a general agreement that mitigation—reduction of our carbon dioxide (CO₂) emissions—alone will not solve the problem, that we will have to pursue a dual strategy of both mitigation and adaptation. We will have to defend our cities against both sea level rise and the consequences of more frequent and severe storms, droughts, and heat waves. This raises fundamental questions about the basic principles and assumptions of our current aging infrastructure. It raises broad, complex, and daunting questions about how we can create more resilient communities that encompass all the dimensions of city building. Given this moment of opportunity, the problem demands that we act with greater urgency, that we question our current modes of thinking and development practices. There have been many ideas for creating greater resilience in the post–Hurricane Sandy New York region—from floodgates to more pervious infrastructure. Robert Yaro, president of the Regional Plan Association, states:

There are many steps that the region should consider to help reduce damage from the inevitable storms in our future, from physically protecting urban shorelines to rethinking our transit and power networks so that localized outages don’t cripple an entire city or region. In all likelihood, we will need to adopt both “hard” infrastructure changes and “soft” solutions that rely on better land-use decisions and tap ecological systems to limit damage.¹

In the past, efforts at climate mitigation have focused primarily on the building scale (low- to zero-energy buildings) and the large utility scale (solar and wind farms in remote locations). While there has been great progress in the energy efficiency of buildings over the past forty years, buildings alone do not include the transportation and infrastructure systems (energy, water, and waste) as part of the design process, and large renewables in remote locations rely on long, inefficient, and vulnerable power lines. Increasingly, the neighborhood scale (from city block to district) is being recognized as an opportunity because it aggregates all the systems and flows. It has the potential to integrate the design of transportation, buildings, and infrastructure while engaging the design of the public realm as part of the system. It also has the potential to become its own micro-utility. These potentials have been recognized in part by the creation of the Leadership in Energy and Environmental Design for Neighborhood Development (LEED-ND) rating system. The whole-systems opportunities are part of architect Peter Calthorpe’s argument that “responding to climate change and our coming energy challenge without a more sustainable form of urbanism will be impossible.”²

If neighborhoods can become their own micro-utilities, supplying most if not all of their energy while recycling their water and waste, this represents a whole-systems approach, which is much more resilient. As a micro-utility, each neighborhood can continue to operate if the central infrastructure goes down. As an added benefit, development can take place incrementally without adding significantly to existing infrastructure loads. The case studies presented in this book are the first efforts at this kind of whole-systems thinking, and the lessons learned point to a new way of doing business.

The case studies also show that to truly drive change, resilient communities need to be places where people want to live and places that are accessible to all. At various scales, a compelling design that makes the environmental benefits clear has been proven to be critical in gaining support and investment. Paradoxically, who would imagine that this point would be made clear in a car advertisement? Yet consider the opening lines of this advertisement for the Chrysler 300: “If you want to make a fuel-efficient car, the first thing you have to do is design a car that is worth making.”

The message is clear. Fuel efficiency alone is not enough. You have to provide the “styling,” quality, luxury, and identity that people want, with fuel efficiency an expected side benefit. The advertisement ends with the Chrysler 300 pulling into the driveway of Frank Lloyd Wright’s beautifully restored Gregor S. and Elizabeth B. Affleck House, reinforcing the message that design matters. Americans can now have it both ways—fuel efficiency with hip design, “imported from Detroit”!

The advertisement is Detroit’s response to the Toyota Prius, arguably one of the most innovative and energy-efficient ventures into the car market— and, for many, one of the ugly ducklings. Beyond the technological wizardry of its hybrid gas and electric power drive and the energy recovery of its flywheel braking system, the more profound innovation is its real-time feedback on the energy performance (in miles per gallon) of driver behavior. The real-time feedback allows us to play the game (Homo ludens)³ “How efficient can we get?,” and we love to beat the system. Surprisingly, in designing hip neighborhoods with low- to no-carbon performance, both technical wizardry and user engagement in the process—“the game”—are essential.

This book explores the best practices of first-generation efforts to create low-carbon neighborhoods. It demonstrates the value of system design at the neighborhood scale. Most important, it points to how to achieve a more distributed and resilient infrastructure. It also shows that “human agency,” the involvement of the residents in the process, is essential in achieving the goals. All of the systems and benefits are not just technological. In fact, many of the “green,” sustainable strategies are out in the open, enhancing the richness and experience of people’s everyday lives. It is these cobenefits, many related to health and well-being, that help to create the distinguishing design identity of the neighborhoods that residents desire. The strategies point to a greatly expanded role of the public space in cities—not only to provide the space for public activities but also to play a part in the whole-systems design of infrastructure. The book focuses on a select group of existing first-generation neighborhoods that have attempted to make this final step to sustainability: in Sweden, Bo01 in Malmö and Hammarby Sjöstad in Stockholm, and in Germany, Kronsberg in Hannover and Vauban in Freiberg. Each case-study chapter looks at the planning process, transport, urban form, green space, energy (consumption, generation, and distribution), water, waste, and social issues. The case studies are followed by a chapter that compares the four neighborhoods, and then a significant chapter looks at the lessons learned for the United States, focusing on opportunities for infilling or retrofitting existing areas. The paradox of the US city-building process, especially as it relates to suburban sprawl, is that the resulting pockets of abandonment and underdevelopment are now potential opportunities for sustainable neighborhood development, both within the core cities and in the multiple phases of suburban sprawl. Three of the four case studies seized this opportunity (Bo01, abandoned shipbuilding and manufacturing; Hammarby Sjöstad, obsolete industrial manufacturing site; Vauban, former military barracks), and similar conditions exist throughout the United States.

Why Bo01 and Hammarby Sjöstad (Sweden), Kronsberg and Vauban (Germany)

The case for studying low-carbon neighborhoods first emerged for me in 2006 while I was conducting a graduate interdisciplinary studio at the University of California, Berkeley, on transit-oriented neighborhoods for Tianjin, China.⁴ We discovered not only that compact, high-density, mixed-use, walkable neighborhoods around transit stops could dramatically reduce the need for and use of the car but also that they could become zero carbon in operation through the application of energy-efficient design strategies to reduce demand combined with renewable energy supply from local wind, solar photovoltaics, and, surprisingly, capture of energy from the waste streams. This discovery led to the development of the EcoBlock concept in collaboration with the San Francisco engineering firm ARUP.⁵ Its principles and strategies are currently being applied in the development of a new zero-carbon green campus design for Tianjin University, the first in the world. During the evolution of the EcoBlock concept, the question occurred as to whether a similar kind of integrated, whole-systems approach to neighborhood design had been attempted elsewhere in the world, and if so, whether there were any performance data. Fortunately, during this same period I was able to take a yearlong sabbatical and decided to conduct a global search to discover any precedents and best practices of whole-systems thinking at the neighborhood scale similar to the EcoBlock concept. Not surprisingly, very few have been built and performance data have been collected for even fewer; nonetheless, there have been enough to inspire a comparative analysis of the four case studies chosen.

In conducting my search, I established a simple set of criteria related to sustainability. It seemed that each neighborhood should be large enough, at least 1,000 units, to generate sufficient flows of energy, water, and waste to enable potential borrowing, balancing, and stealing among systems; that each should be mixed-use with at least a 30 percent jobs-to-housing balance within a reasonable walking or biking distance; that each should have a convenient public transit system with good and frequent connections to jobs and services; and that each should have set aggressive goals for energy and water conservation with equally aggressive goals for recycling and waste treatment. In addition, I was looking for neighborhoods that integrated into their planning process goals for generating most or part of their energy from local renewables. But most important, I was looking for neighborhoods that had been in existence (in whole or part) long enough for performance data to have been collected.

While specific criteria related to sustainability were critical, I was searching equally for projects with clear ambitions about a high-quality built environment for the residents—where the urban design, the architecture, the landscape, and the design of the public realm were as important as the goals for sustainability. In other words, I was looking for projects that demonstrated an integrated approach to urban design and sustainability, ones in which sustainability was not the only goal. I was curious whether there were any conflicts between the two, and if so, what trade-offs were made and whether they affected performance.

These criteria quickly eliminated several smaller iconic projects, such as London’s one-hundred-unit Beddington Zero Energy Development (BedZED), even though it has one of the most innovative whole-systems approaches in both urban design and sustainable systems. The criteria also eliminated some of the newer projects, such as the Greenwich Millennium Village, in London, and Sarriguren, outside of Pamplona, Spain, for lack of performance data. Ørestad, on the southwest edge of Copenhagen, has excellent subway and rail access to both the downtown and the international airport, but so far it is composed of large “object” buildings on big blocks with limited entrances and street access. The result is high-style signature buildings with a bland and sterile pedestrian environment, in surprising contrast to the vibrant pedestrian environment of Copenhagen. Furthermore, beyond its medium-density, transit-oriented development, no other integrated energy, water, or waste strategies for sustainability are evident at the neighborhood scale.

In looking carefully at all five continents, I discovered that there were dozens of projects in the planning and development phases (witness the sixteen founding projects chosen for the William J. Clinton Foundation’s Climate Positive Development Program),⁶ but only a handful had been built and occupied long enough to have performance data. The lack of models that accomplish this was highlighted by Lord Nicholas Stern at the closing of the Copenhagen Climate Change Conference in 2009. In response to a question about the impediments to achieving a lower-carbon future, Lord Stern commented that beyond the economic, legal, and social inertia in our current development practices, we just do not have good alternative models with known performance.⁷

At first, I thought a survey of all eight projects—BedZED, Greenwich Millennium Village, Sarriguren, Ørestad, Bo01, Hammarby Sjöstad, Kronsberg, and Vauban—would be the most useful, but after further investigation I decided that a detailed comparison of the best four would be even more instructive and would provide a more precise set of lessons learned. Using my selection criteria and the desire to choose only the best practices, I quickly zeroed in on the latter four projects, which are covered on the following pages.

Beyond meeting the basic selection criteria, Bo01, Hammarby Sjöstad, Kronsberg, and Vauban together demonstrate the four possible strategies for generating energy from local renewables—wind, solar, geothermal, and waste—each with a different emphasis and combination. They represent the first integrated “wizardry under the hood.” Bo01 uses local wind generation to power a geothermal ground- and ocean water heat pump for heating and cooling. Hammarby Sjöstad has three different waste-to-energy systems: the first burns combustible garbage to power a local district heating and electric cogeneration plant, the second recovers heat from the sewage treatment system, and the third converts sludge to biogas for cooking (1,000 units) and to power local buses. Kronsberg has two large-scale wind machines (3.2 megawatts) that generate 50 percent of its electricity; a gas-fired heating and electric cogeneration plant provides the other 50 percent. Vauban has a local heating and electric cogeneration plant powered by waste wood chips from the city. It also has a section that demonstrates the most successful solar strategies, combining a model passive solar direct gain system for heating and a rooftop photovoltaic array for electricity, delivering an additional 15 percent energy back to the city.

All four neighborhoods demonstrate good energy conservation standards, with Kronsberg and Vauban having sections that meet the very aggressive “passive house” standard of 15 kilowatt-hours per square meter per year (kWh/m²/y) for heating. Together, the neighborhoods have employed all types of solar collection. Bo01 uses evacuated tube collectors to assist the district heating system. Hammarby Sjöstad uses flat-plate panels and evacuated tubes to preheat water for domestic use. As a test case, Kronsberg combines a large solar hot-water array with a large seasonal storage tank in order to capture summer solar energy to augment winter solar heating. All four neighborhoods have applied photovoltaic arrays to buildings. Hammarby Sjöstad has vertical arrays on south-facing walls and Kronsberg has them on rooftops, primarily for demonstration purposes. Bo01 also has photovoltaics for demonstration, while Vauban has a more aggressive deployment of photovoltaics on the roofs of residential units and on large parking structures. All four neighborhoods have well-developed systems for solid waste collection, with Bo01 and Hammarby Sjöstad using evacuated tube systems. In addition, all four have developed on-site storm-water management systems that create significant landscape design features. On the other hand, none has employed a local sewage treatment system or recycling; each relies entirely on the city’s central facilities for sewage treatment and on the city’s supply of potable water.

The full array of sustainability strategies outlined in this book provide rich dimensions for comparison. A comparison of the different principles and strategies using real performance data can reveal which strategies are the most critical in achieving low-carbon and low-energy goals. It also allows us to assess which strategies might contribute to the greatest resilience. The various reports on each of the neighborhoods prepared by multiple agencies provide some performance data, but many gaps and inconsistencies exist. Not surprisingly, collection of performance data has been extremely difficult because of the complexity of the neighborhood systems, the multiple agencies involved, and the lack of carefully developed monitoring plans to begin with. The power companies, utilities, and agencies have had to rely on normal metering systems that would be installed on any project to collect gross data. Without additional meters and sensors, it has been impossible to break down the performance of individual systems. Nonetheless, by cross-referencing the multiple reports from different agencies and interviewing some of the key people involved, my students and I have been able to piece together a reasonable set of data. One goal of this book is to provide a set of measures, a framework by which to compare these dimensions of sustainability. The hope is to create a baseline of performance not only to determine what these first-generation whole-systems strategies can achieve but also to establish a benchmark for comparing future performance of the dozens of sustainable (zero-carbon to plus-energy) neighborhoods that are on the drawing boards or in the approval process.

Of course, innovative strategies for sustainable neighborhoods do not occur on their own. By necessity, they are the result of a development process. In case ...