Low-impact+materials

SUSTAINABLE RESIDENTIAL DESIGN: USING LOW-IMPACT MATERIALS

Coen + Partners, Inc. || New and non-recyclable materials used in homes and landscapes consume enormous amounts of resources to produce and distribute, and then create additional waste when they are demolished -- they often aren't originally designed to be recycled. Waste materials create waste landscapes: landfills, massive incinerator systems, and multi-square-mile floating plastic garbage islands in the world's oceans.
 * [[image:http://www.asla.org/uploadedImages/CMS/Resources/lowimpactmaterials_page.jpg caption="low impact materials page"]] ||
 * Speckman House Landscape, Highland Park, St. Paul, Minnesota.

Through "integrated site design," a comprehensive approach to sustainable building and site design, sustainable residential landscape architecture practices can not only improve water and energy efficiency, but also reduce waste. If part of a broader integrated site design, sustainable residential landscape architecture can eliminate waste created from producing and using design materials.

Integrated site design is a framework for increasing the quality of the built environment and involves//maximizing existing natural systems to produce and apply low-impact materials.// These types of designs leverage the many benefits of natural systems, thereby significantly cutting down the use of materials that release toxic substances and fill up landfills.

Homeowners can significantly increase the quality of the environment through the use of innovative low-impact materials. These materials include permeable, recycled, recyclable, reflective (high albedo), and non-toxic materials. Using these materials can minimize consumption of newer materials, enable a continual reuse of limited natural resources, and decrease waste and environmental pollution. Used in both landscapes and buildings, low-impact materials can reduce CO2 emissions.

Local governments are also partnering with non-profit organizations to increase public awareness about using sustainable residential design practices to apply innovative, low-impact materials. PERMEABLE MATERIALS

Rainfall picks up contaminants from impervious surfaces such as asphalt and concrete streets, driveways, and other pathways, which further contribute to water pollution. In comparison, using permeable materials allows natural filtration and reduces the costs associated with adding stormwater management systems.

Permeable materials have porous surfaces that mitigate and control stormwater runoff by allowing water to pass through into the underlying soils. Permeable materials enable stormwater to be filtered through natural soil percolation. This kind of natural filtration process is the most effective way of eliminating water contaminants and pollutants.

Residential driveways and walkways can incorporate permeable materials and significantly reduce stormwater runoff while still maintaining a high-level of aesthetic quality. Often, these materials are also more reflective, which can help decrease the heat island effect.

CERTIFIED WOODS

Using new, natural woods, particularly tropical hardwoods, is an inefficient use of increasingly scarce hardwood resources. Using certified, sustainably harvested woods helps preserve forests, which are critical to sequestering CO2 emissions.

Certified woods refer to harvested woods that originate from responsibly managed forests. These woods are certified through an independent organization that issues standards for sustainable forest management.

Sustainable forest management enables lumber companies to harvest wood for materials while conserving forest ecosystems and preserving natural habitat. Sustainable forest management ensures a stable source of lumber and minimizes adverse environmental effects, such as soil erosion, stream sedimentation, water and air pollution, and waste production.

Some woods, including tropical hardwoods, need to be preserved as they are central to fragile rainforest ecosystems. A few innovative firms are now treating sustainably-harvested softwoods with non-toxic coatings to make them harder so they can be used as replacements for natural hardwoods. RECLAIMED AND RECYCLED LOCAL MATERIALS

Approximately 30 to 40 percent of the waste found in landfills is construction and demolition debris. Reclaiming and reusing salvaged materials can reduce costs by eliminating the use of pristine resources in new materials and limiting the amount of waste sent to landfills.

Demolished local building materials can be retrieved and reused locally, saving energy. As a result, local reclaimed and recycled materials reduce construction and transportation-related CO2 emissions. At the same time, recycling used building materials reduces burdens on stressed local waste management systems.

Using local materials also supports the growth of local recycling businesses. Re-using building construction waste provides economic development opportunities, particularly for depressed economic areas already on the receiving end of municipal or local waste products. //Sources: Green Building Elements // RECYCLED CONTENT

Recycled content refers to the use of recycled materials in new sustainable materials and it can be used to transform used (yet still useful) materials into new products. Using materials with recycled content reduces dependence on new materials and minimizes deforestation. Materials with a high percentage of recycled content also tend to last longer, and therefore reduce waste, energy use, and pollution.

Recycled content into new landscape materials also creates economic development opportunities. According to the California Integrated Waste Management Board, recycling 15,000 tons of material results in nearly 10 new jobs. In contrast, sending the same amount of materials to landfill results in one new job. Recycled content helps create a healthier, smarter economy. //Sources: EcologyAction // REFLECTIVE MATERIALS

Solar reflectance has a significant impact on surface air temperatures in the built environment. Materials with low solar reflectance absorb a larger amount of solar energy, which leads to higher air temperatures and increased energy use. Using reflective, "cool," or white materials reduces energy costs by minimizing the use of air conditioning to cool buildings.

Reflective materials offer high solar reflectance – they have an innate ability to reflect sunlight and reduce solar heat absorption. These materials can stay cool in the sun and also have high thermal emittance – they radiate instead of absorb heat.

Reflective materials also last longer than conventional materials -- materials that absorb heat break down faster.

U.S. Energy Secretary Steven Chu has actively promoted the use of reflective roofs and roadways as a cheap and effective way to reduce CO2 emissions. Chicago recently issued a reflective roof ordinance, and California has announced new reflective roof rules for government-financed buildings. ADHESIVES, PAINTS, COATINGS, AND SEALANTS

Traditional adhesives, paints, coatings, and sealants often contain high levels of volatile organic compounds (VOCs) that increase air pollution. VOC emissions also contribute to ground-level ozone, which increases respiratory diseases such as asthma.

VOC-intensive products are applied to materials to make them shiny and create aesthetically pleasing finishes.

There are now a range of low-VOC products that reduce harmful environmental effects. Using adhesives, paints, coatings, and sealants that have zero or low amounts of VOC content can increase air quality and reduce environmental pollution. Zero-VOC materials are odorless and water-based, making them easy to clean up. As a result, disposal of unused materials doesn't harm the environment and reduces toxic control expenses. []