Sustainable Landscape Construction

A Guide to Green Building Outdoors

By Kim Sorvig, J. William Thompson

ISLAND PRESS

Copyright © 2018 Kim Sorvig and J. William Thompson
All rights reserved.
ISBN: 978-1-61091-810-7

Contents

List of Figures,
List of Tables,
Preface to the Third Edition,
Authorship Changes,
Why a New Edition?,
What’s New in This Edition?,
Who Should Use This Book?,
How to Use This Book,
Finding Landscapes Along the Information Highway,
Acknowledgments,
Contacting the Author,
Basic Principles: “Sustainability” in Context,
What Is Sustainability? Politics, Ethics, and Semantics,
Sustainability: Convention, Tradition, and Innovation,
Landscapes Against Climate Change,
Sustainability, Substance, and Style,
Rethinking Special Landscape Types for Sustainability,
Principle 1: Keep Healthy Sites Healthy,
What Is a Healthy Site?,
Take a Role in “Pre-construction”,
Do Your Homework First: Knowledge as Sustainability,
Avoid Survey Damage,
Minimize Utility Damage,
Physically Protect Sites During Construction,
Preserve Healthy Topsoil,
Save Every Possible Existing Tree — Even Just One,
Use Appropriate Construction Machinery,
Related Design and Planning Issues,
Coordination and Follow-up,
Principle 2: Heal Injured Soils and Sites,
Turn Wastelands to Gardens,
Balance the Environmental Costs and Benefits of Restoration,
Involve the Community in Site Restoration,
Make a Virtue of the Necessity for Landfills,
Recognize Agricultural and Rural Restoration,
Restore Landscapes Structurally,
Restore Damaged Soils On-site,
Restore Regionally Appropriate Vegetation,
Restore Forests and Coexist with Wildfire,
Principle 3: Favor Living, Flexible Materials,
Highlight the Benefits of Vegetation,
Hold Slopes in Place with BTEC — Biotechnical Erosion Control,
Make Vertical Structures “Habitat-able” with Greenwalls,
Turn Barren Roof Spaces into Greenroofs,
Construct for and with Plants,
Evaluate Turf: The Green, the Bad, and the Ugly,
Count on Plants to Sustain,
Principle 4: Respect the Waters of Life,
Work with the Site’s Water Regime,
Understand, Protect, and Restore Natural Wetlands,
Know the Issues Before Working in or near Wetlands,
Restore Rivers and Streams to Full Health,
Collect and Conserve Water,
Irrigate Intelligently and Sparingly,
Reuse Graywater,
Purify Water at Every Opportunity,
Test Modern Hardware for Cleaner Piped Stormwater,
Let Constructed Wetlands Treat Water,
Principle 5: Pave Less,
Plan and Design to Reduce Paving,
Take Advantage of Context-sensitive Road Design,
Use Techniques That Reduce Runoff from Paving,
Use Porous Paving Materials,
Cool Asphalt with Planting and Albedo,
Principle 6: Consider Origin and Fate of Materials,
The Devil Is in the Details,
Recall Some Simple Guidelines,
Let Reuse Be Re-inspiration,
Use Local, Salvaged, or Recycled Materials,
Evaluate Environmental Costs When Choosing Suppliers,
Use Sustainably Harvested Renewables,
Use Nonrenewable Materials Sparingly,
Avoid Toxic Materials,
Know General Toxicity Issues by Material Type,
Avoid Three Controversial Materials,
Prioritize Hazard-reduction Efforts,
Principle 7: Know the Costs of Energy over Time,
Understand How Landscape Energy Use Is Different,
Manage Energy for Machines, Tools, and Labor,
Embodied Energy — Why Do We Care?,
Use Life-cycle Costing to Justify Sustainable Design,
Apply Guidelines for Landscape Energy Conservation,
Principle 8: Celebrate Light, Respect Darkness,
Respect the Need for Darkness,
Talk Lighting — a Brief Glossary,
Use Lighting Efficiently,
Try Low-voltage Lighting for Flexibility,
Use Solar Lighting,
Evaluate Lamp Performance,
Join the LED Lighting Revolution,
Principle 9: Quietly Defend Silence,
Understand Noise Terminology,
Be Aware of Damage Caused by Noise,
Don’t Rely on Noise “Barriers” in Most Landscapes,
Try Noise-absorbing Materials,
Modify Pavement to Reduce Road Noise,
Make Noise Invisible,
Fight Noise with Noise,
Push for Quieter Landscape Tools,
Protect “Soundscapes” Through Planning,
Principle 10: Maintain to Sustain,
Know the Resource Costs of Conventional Landscape Maintenance,
Plan for Maintainable Spaces,
Expect Change,
Evaluate Bio-based Maintenance Products with Care,
Apply Integrated Pest Management,
Use Fertilizers Sustainably,
Don’t Waste On-site Resources,
Consider Alternatives to Mowing,
Adapt to Using Native Plants,
Manage Large Public Landscapes Holistically, Too,
Evaluate Life-cycle Costs of Maintenance Options,
Use Innovative Funding,
Coordinate Design, Construction, and Maintenance,
Principle 11: Demonstrate Performance, Learn from Failure,
Anatomy of a Certification System,
Landscape Certification Programs,
Better Measures,
Landscape Forensics and Learning (or Not) from Failure,
Sustaining Principles, Evolving Efforts,
Learning from the Landscape: Themes and Strategies,
Green Education in Design and Construction,
Landscapes as Public Environmental Education,
Thinking One Hundred Years Ahead,
Notes,
Index,

CHAPTER 1

Basic Principles: “Sustainability” in Context

If we put our minds to it, can we gardeners, with our centuries of practical experience, help rescue species from the brink of extinction?

— Janet Marinelli, Stalking the Wild Amaranth: Gardening in the Age of Extinction

Concern for the health of outdoor places is a central theme in landscape architecture and landscape contracting, and has been since long before “sustainability” was a word. “Stewardship” is almost the mantra of the American Society of Landscape Architects. It is a concern shared by many members of related disciplines like architecture, planning, public-lands administration, and horticulture, as well as by private gardeners. Yet in translating this concern to the materials and methods of making landscapes, there frequently seems to be a disconnect between ethical intentions and practical actions.

Several landscape theorists have suggested that landscape architecture and construction (as opposed to land-use planning at the larger scale) have nothing to contribute to a sustainable future. Many practitioners feel that landscapes are (or even should be) merely decorative. Others have simply declared landscape architecture dead. While sympathizing strongly with the perception that landscape architecture as conventionally practiced is dead to current realities and has next to nothing to contribute to them, I hold with those who see changes in landscape-making as serious and essential parts of a livable future (for humans and nonhuman species). More proactive writers have identified ways to improve environmental practice and education. (See p. 414.)

Those who believe that sustainability is essential in the landscape, and vice versa, must address these concerns. One way to start is by looking at the context in which the landscape professions exist and operate — the definitions and conventions, policies and politics that surround sustainable practice.

Designers are used to focusing within their project boundaries. Thinking outside this box, more and more landscape professionals approach each project as part of an open regional system of natural and cultural elements. Although this way of thinking has ancient roots, it began to acquire modern momentum in the 1960s and ’70s, with books like Silent Spring,The Limits to Growth, and Design with Nature. The questions raised by those books are still critical, the answers still evolving. What are the relationships between human technology and nature? What concepts can best guide people to live within our ecological means?

For landscape professionals, the central question is: how can people make environmentally responsible choices in the process of conceiving and constructing landscapes? In a book of technical strategies, such questions are of real importance. Without considering the big picture, it is nearly impossible to make good decisions on a project-by-project, site-by-site scale.

At the national scale, urban and suburban development reshapes millions of acres of previously undeveloped land each year — at the peak of the housing bubble in Colorado alone, ten acres per hour by one estimate. While worries about development usually focus on structures — tract homes, commercial strips, and industrial buildings — the constructed landscapes that accompany these buildings also contribute to widespread environmental change, and sometimes damage. When self-sustaining ecosystems are converted to built landscapes, the hidden costs may include soil loss, degradation of water, toxic and nonrenewable materials, and unsustainable energy use. These costs are unacceptable, but also largely avoidable.

Compare an ordinary quarter-acre landscaped lot with a two-thousand-square-foot house, each a mainstay of the American Dream. The landscape directly affects an area of environment five and a half times as large as the house. More important, if the landscape introduces toxic materials and invasive plants or diseases, they are free to spread; inside the house, such problems might be contained or controlled by walls, filters, or mechanical systems. In addition, many landscape practices are “nonpoint” sources of pollution, crossing ownership and jurisdictional lines.

Historically, some of the green of the garden has been lost in the broader battle to “control” nature. Social expectations of appearance, style, and conformity bring heavy doses of industrial-strength technology into the landscape. To pretend the technology is not there is to continue the myth that gardens are 100 percent natural. This myth, ironically, plays into the hands of those who would happily accept all landscape technology as equally wholesome, and let constructed environments replace natural ones everywhere.

If a new generation of designers and a new era in design is to contribute meaningfully to sustainability, it is critical to think carefully about context, values, and goals. Sustainability is a framework, a systematic way of linking ourselves with the natural systems that support us. Without that framework, individual green buildings and restored landscapes will not add up to what is really wanted: a worldwide network of healthy places that sustain people and sustain themselves.

The first contextual issue that requires clear thinking is the idea of sustainability itself.

What Is Sustainability? Politics, Ethics, and Semantics

Despite its widespread popularity, “sustainability” is far from having a clear and agreed definition. Although the core vision seems simple — a lasting and nondestructive way to live on this Earth — the questions are many. It is important for those of us concerned with landscape construction to think clearly about the local good or damage that we do and about opportunities and limits that link our site-by-site actions to a global picture.

Probably the simplest widely used general definition of sustainability is meeting the needs of today’s population without diminishing the ability of future populations to meet their needs. The concept of a sustainable landscape also has a significant history. (In this book “landscape” is inclusive of wild outdoor spaces and constructed ones, functional or frivolous, at scales ranging from tiny yards to biologically consistent regions — J. B. Jackson notwithstanding.) The Council of Educators in Landscape Architecture (CELA) published a definition in 1988, most of which remains valid today: sustainable landscapes “contribute to human well-being and at the same time are in harmony with the natural environment. They do not deplete or damage other ecosystems. While human activity will have altered native patterns, a sustainable landscape will work with native conditions in its structure and functions. Valuable resources — water, nutrients, soil, et cetera — and energy will be conserved, diversity of species will be maintained or increased.”

One increasingly important concept in defining sustainability (and in measuring and verifying the performance of “green” projects) is that of “ecosystem services.” This concept recognizes that almost all human work, invention, and economics depend entirely on materials and processes that are not human in origin, that is to say, on what used to be called “the bounty of Nature.” These more-than-human processes include fundamental life support like the creation of living soil; “provisioning,” such as food, fuel, water, and materials; “regulating services,” such as cleaning the air, balancing the pH of water bodies, etc.; and “cultural services,” such as artistic, spiritual, recreational, and therapeutic imagery and concepts originating in nature. A more or less complete list of ecosystem services is part of Principle 11. One definition for sustainability would be “maintaining and not degrading the existing ecosystem services of a site or region.” The Sustainable Sites Initiative, also detailed in Principle 11, bases much of its point-rating system on the ecosystem services concept.

Sustainability (and its near-synonyms) could also be defined in terms of priorities. Conventional modern societies have, until recently, tended to prioritize economic growth über alles. Sustainability sets the long-term health of humans, other species, and the planet as equal to or higher than economics per se. The field of “ecological economics” studies how this should be implemented. For practical purposes, one of the differences in sustainable priorities versus conventional ones is called the Precautionary Principle. This states that, if the results of a product or technology are unknown or disputed, it should not be used, responding to risk with what lawyers call “an abundance of caution.” By contrast, conventional policy makers and businesses treat risk as something to manage: if one person in a million gets sick from exposure to a new chemical that has economic benefits, some of the profits are theoretically set aside to deal with that person’s illness, rather than scrapping the product. This resembles the military concept of “acceptable losses.” Since environmental risks are so often irreversible threats to whole regions or the entire planet, the Precautionary Principle argues that there is no acceptable or manageable level of risk. Corporate-oriented opinion considers this not to be sufficiently “business-friendly,” and accuses those who prioritize sustainability of “killing jobs,” etc. Both approaches have merit at the appropriate scale, but for businesses (or consumers) to put products, prices, and profits ahead of livability and health is irresponsible.

In this book, “contributing to sustainability” means primarily that a method or material appears to minimize waste, pollution, and degradation of the environment. For true sustainability, it is not enough, however, just to acquire and build with the greatest efficiency. “Do I need it?” choices about the scale and appropriateness of proposed landscape changes must also play a role. At times, humans must make sacrifices in favor of maintaining habitat and biodiversity. In these choices, landscape professionals can (sometimes) guide their clients and their communities.

To some degree, “sustainability” has become a buzzword, and fuzzy. The term is bandied about in support of widely different causes and to sell products (including landscape products) only vaguely related to ecology. Some writers have proposed different terms for the concept. “Alternative” is one of these; popular in the 1960s, it implies second-rate status. “Appropriate technology” is also widely used. “Sustainability” seems preferable because it emphasizes long-term appropriateness.

In the 1990s the late John Lyle suggested that sustainability was not enough and that optimal design should be “regenerative” — capable of renewing the energy and materials of degraded ecosystems. Lately, this type of design has been termed “net-positive” (producing more resources — usually energy — than the project uses), in contrast to “net-zero” (using no more resources than the project produces). Sustainability in general, and LEED in specific, have been criticized for endless checklists of what not to do. William McDonough’s concept of cradle-to-cradle material cycles, as well as the Living Building Challenge, attempt to make construction contribute to the planet rather than take away. Serious attempts to accomplish this rely on measuring pre-construction “ecosystem services,” then ensuring that those are still being produced, and more, after construction is complete. Tristan Roberts, EBN‘s chief strategy officer, says being green is not doing the least harm, but is “honoring our bond with the earth at every step of the building process.”

By contrast, at least one group, the Bay Area Stormwater Management Agencies Association (BASMAA), talks about “less-toxic gardens” and “less-toxic methods” of maintaining them. BASMAA, not without cause, implies that human activity will always have some negative impact on nature, particularly when concentrated in large urban areas (which is the current demographic trend).

The roots of sustainable design are in “ecological design,” a term that raises still other misgivings. “Ecology,” especially as a popular movement influencing attitudes toward the land, ranges from highly emotive New Age assertions to rigidly rational species-counting, and proponents can seem bent on saving the world whether the world likes it or not. Some such accusations are so overstated that it is easy to dismiss them, but enough thoughtful concerns have been raised that they must be considered.

“Environmentally responsible” is another frequently used term. Although it is a mouthful, it may yet be the best term: one can take responsibility for attempting something even when the outcome is uncertain, and one can take responsibility for mistakes. “Sustainable,” “regenerative,” “ecological,” and “appropriate” all tend to assume that we can predict the outcome.

Two new terms have emerged to prominence since the second edition: “resilient design” and “passive survivability.” “Resilience” means to take a lickin’ and keep on tickin,’ to use a folk phrase; sites, facilities, and communities need not only to use resources efficiently and be durable, but also to be able to adapt to adverse future conditions. This doesn’t mean that attempts to slow or avoid climate change are abandoned, but resilient communities also prepare for what can’t be avoided. Planning ahead for these possibilities greatly expands the challenge of good design. Resilience relies, among other strategies, on diversity of systems that back each other up; no one technology is “the solution.” Passive survivability is, in a nutshell, buildings that can survive disasters and provide basic shelter despite prolonged supply-chain outages — in situations similar to the recent storms Harvey and Irma. Both resilient and passive-survivable structures rely explicitly on “ecosystem services” to give them adaptability, and many of those services are landscape-related.

Although this book primarily uses the term “sustainability,” the points raised by these alternative terms bear keeping in mind.

The limits of what landscape-makers can hope to contribute must also be acknowledged. The “present/future needs” definition of sustainability can be criticized for oversimplifying several key questions: Which population’s needs are to be met? How large a human population can be sustained? Where to draw the line between needs and desires? It would be naive to ignore the criticisms that have been leveled at the very idea of sustainability. Questions about sustainability, no matter what we call it, have pragmatic and political effects on the construction of landscapes, as they do on almost every human endeavor in the twenty-first century.

The following questions illustrate some of the doubts about sustainability, in terms specific to built landscapes. Operating locally and in isolation, landscape design and construction are unlikely to resolve these questions. With coordinated effort, however, the landscape professions can and must be part of the resolution.

• If nonpolluting, low-maintenance constructed landscapes covered the globe, at the expense of wild species and places, would that be a sustainable world?

• Is there any way to avoid impoverishing the natural world without drastic regulatory limits on human population, land use, and resource consumption?

• For a majority of the world’s population, “landscape” means crops, firewood, and survival. In such economies, public parks and private gardens are fantasies far beyond reach, glimpsed on TV or through closed gates. Does this mean that all landscape construction should be sacrificed to achieve subsistence-level sustainability?

• Is stewardship of the Earth as a whole system possible without dramatic changes in jurisdictional divisions of land?

For some, the answer to these questions is that sustainability is an admirable idea but can never be achieved. True, sustainability may be impossible, or the idea may merely disguise the seriousness of environmental degradation. Yet with due respect, defeatism is neither warranted nor helpful. The critics rightly remind us that there are limits to what sustainability can or even should be; that within those limits, small efforts can yield important results; and that local results in turn can contribute to cumulative global change.

(Continues…)Excerpted from Sustainable Landscape Construction by Kim Sorvig, J. William Thompson. Copyright © 2018 Kim Sorvig and J. William Thompson. Excerpted by permission of ISLAND PRESS.
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