February 7, 2013
LAS VEGAS — The Vinyl Siding Institute is promoting a report that says vinyl siding is more sustainable than most other types of exterior cladding.
The report compares the environmental performance of vinyl siding, insulated siding, cedar siding, stucco, exterior insulation and finishing systems, fiber-cement siding (without recycled content), and bricks and mortar. Along with life-cycle and environmental-impact analyses, the report includes data on the materials' costs, toxicity and impact on human health.
In most areas, vinyl siding outperformed other claddings, according to the report.
Suzanne MacNeil, associate director of communication and marketing for VSI, said the study is entirely fact-based and third-party certified.
"We did not come up with these conclusions. These conclusions presented themselves," she said.
"We're not going to greenwash. We're not going to say we're green [or] say we're environmentally friendly without having the data and facts to back it up," she added.
Washington-based VSI, through collaboration with environmental consulting firm Sustainable Solutions Corp. of Royersford, Pa., said it collected its data from several sources, including published studies and manufacturers.
Much of the data came from life-cycle analysis software called Building for Environmental and Economic Sustainability, which was developed by the National Institute of Standards and Technology and was designed to measure the environmental performance of building products.
This is the first study to include BEES data on fiber cement.
Manufacturers input information about their product into BEES. James Hardie Building Products Inc., the leading manufacturer of fiber-cement siding, does not contribute to BEES, but now a company that makes a comparable product does, according to VSI.
"For the first time ever we were able to look at all the primary claddings. … We were pleasantly surprised by the outcome," MacNeil said in an interview at the International Builders Show, held Jan. 22-24 in Las Vegas.
The study rated environmental performance in two areas. One looked at performance throughout the life cycle. The other looked at different areas of impact — global warming and fossil-fuel depletion, for example.
In both analyses, vinyl and insulated siding performed better than most other cladding. The exception was cedar siding, which outperformed both.
Brick and fiber cement had the most environmental impact. Brick had more than four times the environmental impact of vinyl siding, and fiber cement more than twice the impact, according to the report.
Vinyl gained ground against cedar siding in economic performance. Vinyl siding costs about $2 per square foot, including installation and future maintenance costs, making it the least-expensive cladding (nearly tied in price with stucco). In comparison, cedar siding costs about $6 per square foot.
Vinyl is cheaper to install, has a long life span, and requires little upkeep, according to the report.
"It's just a great product for people who don't want to deal with painting or expensive upkeep and maintenance," MacNeil said.
The material is also lighter and easier to transport, she said. "It's a huge difference."
Vinyl's weight also cuts down on the material's global warming potential, according to the report. Vinyl siding contributes less carbon dioxide per square foot than any material except cedar siding.
The report also looks at embodied energy — the sum of all the energy that goes into a product throughout its life cycle.
Embodied energy is broken down into two categories: fuel energy — the energy released when manufacturing the product; and feedstock energy — the potential energy of the material used in the product. According to the report, feedstock energy is not consumed during manufacturing and doesn't contribute to the creation of CO2 or other pollutants.
Vinyl siding and stucco have the lowest embodied energy — both require about 12 megajoules of energy per square foot — though about one-third of vinyl siding's embodied energy is feedstock energy.
According to the report, about five times more energy is needed to manufacture brick and mortar than vinyl or insulated siding, and fiber cement requires nearly twice as much energy as vinyl.
The report also looks at the potential toxicity of claddings and the impact of chemicals on both the environment and human health.
Vinyl and insulated siding scored lowest on ecological toxicity, meaning they emit lower levels of toxic chemicals — like silver, nitrogen oxides and mercury — into the environment.
They also ranked lowest in human health impact. The study looks at the potential impacts of more than 200 chemicals. Impact is based on emissions during various life-cycle stages and not on increased exposure that may happen in manufacturing facilities, according to the report.
Both vinyl and insulated siding have nearly zero impact on human health, according to the report. Brick and mortar have nearly 300 times the human health impact of vinyl, and fiber cement more than 200 times the impact, according to the report.
Despite what people have heard, vinyl siding does not let off dioxins, MacNeil said.
Some people have concerns about vinyl siding letting off dioxins during house fires, but vinyl doesn't burn unless exposed directly to flames and a large majority of house fires take place inside the home, she added.
According to the report, cement production creates more dioxin than the production of PVC, and diesel trucks, heavy equipment and industrial wood burning all produce more dioxin annually than PVC.
The study is part of a push by VSI to re-educate the industry on vinyl siding. The trade association promoted the report at IBS.
The report is also available for free on VSI's website.
"The industry needs to start recognizing that vinyl isn't what it used to be, or perhaps what they think it is," MacNeil said. "It's [VSI's] job to let them know that it's a sustainable product, it's a beautiful product.
"It's not your grandmother's vinyl siding," she added.