Hardscapes for Sustainable Landscapes
Patios, Decks, Walkways, and Driveways
EC 1535
Reprinted June 2003
A.M. VanDerZanden
Do you want to print a copy?
We recommend downloading the print version (106 K).
First download the free Adobe
Reader, if you don't already have it.
Contents
Reduce, reuse,
recycle
Environmental impact
Maintenance
Materials
Evaluating sustainability
Conclusion
Most residential landscapes include a combination of hardscapes
(patios, decks, walkways, and driveways) and ornamental plants.
As you think about the design, construction, and maintenance
of your landscape, consider how sustainable each component is
and how it could be modified to be more sustainable.
As it relates to hardscape materials, sustainability includes
three key factors:
- How well does the material incorporate the principles of
"reduce, reuse, recycle"?
- What is the product's impact on the environment once installed?
- What are the material's maintenance requirements?
Reduce, reuse,
recycle
Use fewer virgin materials in your landscape. Reuse existing
materials when possible or select recycled products. A number
of new recycled landscape products are available in a variety
of textures and colors. Many combine recycled plastics with wood
by-products. These materials require almost no maintenance and
last longer than wood. They can be used for decks, fences, benches,
and planters.
Back to top
Environmental impact
Hardscape materials vary in their effect on the environment.
For example, pavement prevents water from soaking into the soil,
thus increasing runoff, which can carry contaminants into streams.
Porous materials, on the other hand, allow water to soak into
the soil.
Back to top
Maintenance
It often is easier to evaluate the initial cost of construction
materials than their long-term costs. However, the long-term
maintenance costs of some building materials can be significant.
Before choosing a product, research its initial and long-term
costs as well as its recommended uses. Using a product improperly
not only might be dangerous, but likely will increase your overall
construction and maintenance costs.
The hardscape options listed below vary in their sustainability
and short-and long-term costs. For specific information, consult
a landscape construction reference or a landscape contractor.
Detailed information is available in Sustainable Landscape Construction:
A Guide to Green Building Outdoors by J. William Thompson and
Kim Sorvig.
Always check local regulations to make sure the product you
select is approved for use in your area.
Back to top
Sustainable
hardscape materials
Porous paving
This material can be used for driveways, walks, or patios. It
allows water to pass through to the soil, while providing a solid
surface for human and vehicular traffic.
Bricks
Bricks are durable, and almost 100 percent of fired brick is
usable. Factory seconds and used brick can crushed and recycled
for mulch or for pathways. When bricks are laid on a sand base,
rain and irrigation water can pass through the joints, preventing
runoff. Bricks are relatively easy to install and most homeowners
can tackle small installation projects. Long-term maintenance
cost is low if the bricks are installed properly.
Concrete pavers
Pavers share many of the advantages of bricks. They are durable,
easy to install, have minimal maintenance costs if installed
properly, and allow water to pass through the joints if laid
on a sand base. They come in a wide range of colors and shapes
and can be used for drives, walks, patios, and even sunroom or
porch floors.
Concrete slabs
The setup for pouring a concrete slab can be labor intensive,
but concrete itself is relatively inexpensive. However, the slabs
are susceptible to cracking and are expensive to repair. For
most homeowners, concrete pavers are a viable alternative to
a concrete slab.
Soil cement
In this relatively new process, a small amount of Portland cement
is mixed with native soil on site. It has about two-thirds the
compressive strength of ordinary concrete, but is suitable for
walkways and patios. In naturalistic landscape designs, it has
an aesthetic advantage over pavers, bricks, or concrete slabs.
Generally this product needs to be installed by a professional,
so initial costs might be higher compared to others.
Wood
Decay-resistant species such as redwood are in short supply,
generally harvested from ecologi-sensitive forests, and often
expensive. Redwood salvaged from other structures is a sustainable
choice.
Treated landscape lumber is readily available and, if maintained
prop-erly, can last 1520 years. The safety of wood preservatives
has been a subject of much controversy, particularly relating
to disposal, accidental burning of the wood, and leaching of
preservatives into the soil. The methods and chemicals used to
treat landscape lumber vary, and you should compare options before
purchasing a product.
"Plastic lumber"
These products have only recently become available to homeowners,
but have been commercially available for more than 15 years.
Their composition varies, depending on the manufacturer. In general,
they all resist rot and insects and can substitute for preservative-treated
wood. They generally are not engineered for structural purposes.
Ornamental plants
Plants can be used to create "living" fences and walls,
which often are more attractive-- and sustainable-- than fences
made from wood or metal. However, plants should be chosen carefully
to minimize the amount of fertilizer, pesticides, and water required
to keep them healthy.
Selecting plants that don't require extensive pruning to keep
them in bounds can significantly reduce long-term maintenance
costs. For example, to maintain a photinia (Photinia x fraseri)
hedge 8 feet tall and 4 feet wide requires substantial pruning
at least once a year, if not more. A better alternative would
be an arborvitae (Thuja occidentalis 'Emerald') hedge since this
plant naturally grows to about 8 feet tall and 34 feet wide.
See Plant Selection for Sustainable Landscapes, EC 1534 for detailed
guidelines on plant selection.
Back to top
Evaluating product sustainability
Before purchasing any hardscape material, be sure to evaluate
it on a variety of criteria:
- What virgin materials were used in manufacturing the product?
- Does the product incorporate recycled or reused materials?
- Is the surface water-permeable?
- Was the product treated with chemical preservatives?
- Is the material aesthetically pleasing and appropriate for
your landscape design?
- Does the product have adequate structural strength for your
project?
- How long will the product last?
- How much maintenance will the product require, given your
environmental conditions?
- What are initial product and installation costs?
- How difficult is installation? Can you install the product
yourself, or will you need a contractor?
- What tools and additional materials are needed for installation?
- Is the product available in your area?
- Is the product approved for use in your area?
Back to top
Conclusion
Thoughtful consideration of hardscapes and plants can significantly
increase the sustainability of your landscape. Remember that
a landscape is a long-term investment. You must consider up-front
and long-term costs--both financial and environmental--when you
design and construct your landscape.
Back to top
Prepared
by Ann Marie VanDerZanden, Extension Master Gardener state coordinator,
Oregon State University.
Published June 2001. Reprinted June 2003. |
