Sustainable Landscapes
The advent of high-performance green buildings is causing noteworthy
changes to the traditional notion of the constructed landscape. Landscape
design has typically been an afterthought in the conventional building
delivery system, and in many cases, it is given very low priority. As funding
for a project becomes tighter near the end of construction, it will likely
be the budget for the constructed landscape that will be reduced to the bare
minimum. The outcome of such conventional thinking is that landscape
224 Green Building Design
design is given short shrift, treated apart from the building rather than
integral to it. Today, the role of landscape design in high-performance
building is in a state of transition; some projects treat it conventionally,
while others realize that the role of the site is critical to the performance of
the buildings, both individually and collectively. Among these new roles are
to assist building heating and cooling, help control stormwater and elimi-
nate stormwater infrastructure, treat waste, provide food, and contribute to
biodiversity.
The concept of sustainable landscape predates the contemporary high-
performance green building movement. The term emerged in the vocabulary
of landscape architecture in 1988, when the Council of Educators in Land-
scape Architecture defined it as landscapes that contribute “. . . to human
well-being and at the same time are in harmony with the natural environ-
ment. 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, etc.—and energy will be conserved, diversity of species will be
maintained and increased.”11 The movement to reconsider the role of land-
scape architecture was initiated by John Tillman Lyle with the publication of
his 1985 book, Design for Human Ecosystems: Landscape, Land Use, and
Natural Resources. It was almost a decade, however, before more was heard
on the subject of sustainable landscapes. In 1994, two volumes appeared,
coincidentally at the onset of the American green building movement:
Robert Thayer’s Gray World, Green Heart: Technology, Nature and the
Sustainable Landscape, and another book by Lyle, Regenerative Design
for Sustainable Development.
In Design for Human Ecosystems, Lyle considered how landscape, land use,
and natural resources could be shaped to make the human ecosystem function in
the sustainable ways of natural ecosystems. He suggested that designers must
understand ecological order and how it operates at a wide variety of scales, from
minute to global. The understanding of ecological order has to be linked with
human values in order to develop solutions that are long-lasting, beneficial, and
responsible.
In Gray World, Green Heart, Thayer notes that landscape is the place where
“. . . the conflict between technology and nature is most easily sensed.”
A sustainable landscape, according to Thayer, would have the following
properties:
An alternative landscape where natural systems are dominant.
A landscape where resources are regenerated and energy is conserved. A landscape that allows us to see, understand, and resolve the battle between the forces of technology and nature.
A landscape where essential life functions are undertaken, revealed, and
celebrated.
A landscape where the incorporated technology is sustainable, the best of all possible choices, and can be considered part of nature.
A landscape that counters the frontier ethic of discovery, exploitation, exhaustion, and abandonment with one where we plant ourselves firmly, nurture the land, and prevent ecological impoverishment.
A landscape that responds to the loss of place with reliance on local
resources, celebration of local cultures, and preservation of local ecosystems.
A landscape that responds to the view that landscape is irrelevant by making the physical landscape pivotal to our existence.
Chapter 8 The Sustainable Site and Landscape 225
Thayer admits that this vision is utopian but suggests that such a vision is
needed to give us direction. He goes on to provide five characteristics of a
sustainable landscape that are based on the function and organization of natural
landscapes:
1. Sustainable landscapes use primarily renewable, horizontal energy12 at
rates that can be regenerated without ecological destabilization.
2. Sustainable landscapes maximize the recycling of resources, nutrients,
and by-products, and produce minimum waste or conversion of mate-
rials to unusable locations or forms.
3. Sustainable landscapes maintain local structure and function and do not
reduce the diversity or stability of the surrounding ecosystems.
4. Sustainable landscapes preserve and serve local human communities
rather than change or destroy them.
5. Sustainable landscapes incorporate technologies that support these goals
and treat technology as secondary and subservient, not primary and
dominant.
As a cautionary note, Thayer also tells us that “Without sustainable values,
landscapes designed to be sustainable will be misused, become unsustainable,
and fail.” Contemporary American culture does not have a sense of, nor does it
value, place, and it is oriented toward consumption, profit, and waste. Creating
a sustainable landscape in the face of these values is challenging but necessary to
at least launch a countermovement that values nature and ecosystems and that
helps increase human awareness of their role in daily life (see Figure 8.3).
In Regenerative Design for Sustainable Development, Lyle introduced
designers of the built environment to the concept of regenerative landscape,
reminding them, as John Dewey did in 1916, that “. . . the most notable dis-
tinction between living and inanimate things is that the former maintain
themselves by renewal.”13 He maintains that the developed landscape, the one
created and built by humans, should be able to survive within the bounds of
local energy and materials flows and that, in order to be sustainable, it must be
regenerative, which, in the case of landscape, means being capable of organic
self-renewal. Landscapes must be created using regenerative design, that is,
design that creates cyclical flows of matter and energy within the landscape.
According to Lyle, a regenerative system is one that provides for continuous
replacement, through its own functional processes, of the energy and materials
used in its operation. A regenerative system has the following characteristics:
Operational integration with natural processes and, by extension, with social processes
Minimum use of fossil fuels and man-made chemicals, except for backup applications
Minimum use of nonrenewable resources, except where future reuse or recycling is possible and likely
Use of renewable resources within their capacities for renewal
Composition and volume of wastes within the capacity of the environ-
ment to reassimilate them without damage
Lyle gained considerable experience with regenerative landscapes as a
professor at the 1-acre Center for Regenerative Studies that he founded at
California State Polytechnic University in Pomona, where faculty and students
worked with regenerative landscapes and technology to try to solve the daily
226 Green Building Design
Figure 8.3 (A) The landscape design for NASA’s Space Life Sciences Laboratory at
Kennedy Space Center in Florida is self-maintaining and was envisioned as a model of
environmental site design, with over 60,000 square feet of native grasses and wildflowers.
(B) The building orientation reduces heat load and minimizes encroachment into isolated wetlands. (Photos from Zamia Design, Inc.)
problems of providing shelter, food, energy, and water and dealing with waste.
He and his students took what was then a compacted cow pasture within sight of
a large landfill and created what a former center director, Joan Stafford,
described as a landscape that “. . . now yields armfuls of scented, exuberant
lavender, sage, [and] rosemary, growing from rejuvenated soils.”
Chapter 8 The Sustainable Site and Landscape 227
TABLE 8.2
Principles of Sustainable Landscape Construction
Principle 1: Keep sites healthy. Ensure that biologically productive sites with healthy
ecosystems are not harmed by the building project. Special attention must be paid to
utility installation and road construction, which can be especially destructive to natural
systems.
Principle 2: Heal injured sites. Using grayfields, brownfields, or blackfields reduces pressures on biologically productive sites and can result in restoration of blighted properties to productive ecosystems.
Principle 3: Favor living, flexible materials. Slope erosion can be controlled with living
structures rather than artificial physical structures. Greenwalls, artificial structures that
provide a support system for living matter, may be needed in especially steep terrain.
Living materials on roofs create eco-roofs that provide additional green area and assist
heating and cooling.
Principle 4: Respect the waters of life. Water bodies, including wetlands, should be
protected and even restored. Rainwater can be harvested from roofs, stored in cisterns, and used for nonpotable applications. Landscape irrigation should be minimized and landscape designed to be durable and drought-tolerant.
Principle 5: Pave less. Paving destroys natural systems and should be minimized.
Stormwater should be quickly infiltrated through the use of porous concrete and asphalt
paving and through the use of pavers. Heat islands should be minimized by appropriate
landscaping.
Principle 6: Consider the origin and fate of materials. Minimize the impact of landscape materials by carefully analyzing their embodied
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