From the June/July 2009 Issue:

Put on a Greener Face

  • Writer: Nena Donovan Levine

High-performance and low-maintenance are on everyone’s wish list for roofing, siding, and trim. We add “green” to the list of desirable traits of exterior building materials.


Article Photo
enlarge | MiraTEC engineered wood trim resists water, rot, and termites.
Once upon a time the 3 Rs meant reading, riting, and rithmetic. Not any more  nor is anything taught to the tune of a hickry stick, as the old song goes. In this green new world, the 3 Rs mean reduce, reuse, and recycle. The greatest of these is reduce, which often includes reusing and/or recycling. There is a host of high-performance, low-maintenance products for your homes exterior that take those 3Rs at face value.

Green roofing, siding, and trimproperly installedare smart investments. Water, wind, and other weather stay outside, prolonging the buildings life; heated and cooled air stay in, lowering bills; exterior maintenance is reduced; curb appeal increases. Some new materials (such as cedar shingles) are old standards. Others are new products. The timing is perfect for homeowners to replace or shore up these exterior defenses.

Roofs

David E. Cohen, owner of DEC Architects in Princeton, says its a challenge to choose the right roofing. Standard asphalt shingles are really objectionable, he says, because they are petroleum-based and release volatile organic compounds throughout their lifespan. He likes to use cedar shingles, the least expensive of the various green options. When the roof pitch is shallow enough, DEC installs a truly green roof, one planted with vegetation. Cohen lists the benefits, saying a roof planted with vegetation:

" Offsets carbon emissions.

" Insulates from noise and temperature.

" Improves energy conservation inside.

" Reduces storm water runoff.

" Extends the lifespan of the roof.


Patrick LaCorte, senior vice president and principal of DMR Architects and Green Economics in Hasbrouck Heights, is also a fan of green-planted roofs. The foliage is planted in trays that sit atop Firestone TPO, a thermoplastic single-ply membrane, which itself is a heat-reflective material. LaCorte mentions two more benefits:

" Plants are fully grown so the cooling, evaporative effects are instantaneous.

" The aesthetics are great. But note that according to www.greenandsave.com, green roofs cost $8 to $10 per square foot installed, compared with $4 to $6 for an asphalt roof.


If green plantings are a non-starter for your steeply pitched roof, remember a light-colored roof reflects light, so it absorbs less heat and results in a cooler house. So-called smart shingles, made from mineralized polymers to mimic cedar, are a durable (50-year warranty) product from Tamko.

The same website touts the benefits of metal roofs: a useful life three times that of asphalt shingles (50 years vs. 17); good heat reflection; wind- and fire-resistance, perhaps earning you a homeowners insurance discount; possible tax credit; 100 percent recyclable after use. The website also offers ROI (return on investment) calculations for the green products it profiles and, based on certain assumptions, pegs the metal roof ROI at 15 percent.

Also check whether mounting photovoltaic cells on your roof makes sense.

Siding

DMR and DEC Architects like to use cedar siding from a wood source certified by the Forest Stewardship Council. It is renewable and biodegradable, requires a low level of embodied energy to produce, and is often available locally. Cohen also has used HardiePlank siding, made from Portland cement, sand, cellulose fibers, and additives. The color choices are handsome; the finish is warranted for 15 years, the siding itself for 50 years. Portland cement has substantial embodied energy, says Environmental Building News, a respected environmental publication, but the products durability and moisture-resistance are strong attributes. CertainTeed, another prominent brand name, offers WeatherBoards siding and shingles, painted or stained, with a finish warranty of up to 25 years. Instead of Portland cement, WeatherBoards use fly-ash, a product that would otherwise enter the waste stream.

When PVC (polyvinyl chloride or vinyl) siding came on the market in the 1950s, it pushed aside aluminum because it cost less, didnt fade or dent, and installed easily. It is remarkably long-lived, which is why some homeowners like it, but its manufacture and incineration create toxic chemicals, and it cant be recycled safely, Greenpeace says. Some in the industry tout its green attributes, but sustainability gurus such as William McDonough and David Johnson vehemently oppose it.

Trim

DMRs LaCorte specs cedar for trim for its greenness and its pleasing aesthetics. James Hardie International trim products offer the durability of its siding, and the products are endorsed by Peter Pfeiffer of Barley Pfeiffer Architects in Austin, a fellow of the American Institute of Architects and architect of the 2006 award-winning Zero Energy House built in Texas. MiraTEC trim from CMI, is an engineered product made from wood without other commercial value, CEO Bob Merrill says. It resists water, rot, and termites and carries a 30-year warranty. Its shipped primed, not painted.

According to Qualified Remodeler, a trade publication, trim offers a creative way to personalize a house. In fact software now lets contractors upload a photo of your house and apply different trim choices for you to review and revise until youre happy.

Back to You

The universe is expanding, and with it the universe of green websites. The American Institute of Architects and the U.S. Green Building Council sites will get your motor running. They offer solid information and links to pros who will home in on your property. Perhaps you can be the first on your block to sport an undeniably green roof, green as grass  because it is. - DNJ

Nena Donovan Levine
allied member of the American Society of Interior Designers
writer and owner of N Design Inc. in West Hartford Connecticut. �Nena Donovan Levine.


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How Green Is Green?

None of these products is 100 percent green, but a science called life-cycle assessment (or analysis) calculates a products greenness by measuring what goes into making it (inputs) and what comes out (outputs). Inputs are raw materials, energy, and water. Outputs include the product itself and any byproducts, such as air emissions and water pollutants. The basic concept is simple, but LCA isnt easy to do well, according to Environmental Building News. Check out LCA calculation programs at www.epa.gov and www.lcacalculator.com.


For More Information

American Institute of Architects

Cradle-to-Cradle (product life cycles)

Environmental Building News

Forest Stewardship Council

Green and Save

Healthy Building Network

REGREEN (residential remodeling guidelines)

Rutgers Center for Green Building

U.S. Green Building Council