Ask a roofer what a green roof on a commercial building is and he probably has a clear idea of the options. It could be a vegetation roof installed on top of a water-proofing system or a roofing system designed to save on the cost of heating and cooling the building. Or it could be both. Many such systems exist because there's a market for them. Commercial building owners budget to replace their roofs on a regular basis, and reducing energy consumption, as well as prolonging the life of the roof and thus of the building, is always a goal.

Residential Green

But for residential steep-slope roofs, where exactly does green fit in? Obviously no one is going to plant a garden on a gable roof, since it would all slide off in the first hard rain. So is the concept of green roofing restricted to commercial roofing applications?

In Naples, Fla., roofer Ken Kelly, president of Kelly Roofing, doesn't think so. He is convinced that green is the way to go with residential roofing customers, so much so that he puts green roofing front and center on the company website. "Commercial customers are the ones with the deep pockets," he says. "They can afford the $500,000 photovoltaic system or the 5,000-square-foot roof garden. But green is as big an issue in residential as it is in commercial roofing. Homeowners are asking more questions about green than our commercial customers." Driven by changes in the Florida building code and a desire to save on air conditioning bills, Kelly Roofing customers are amenable to suggestions that green products such as solar-powered attic fans be included in their re-roofing jobs.

Interest, Awareness Vary by Market

For those working on residential roofs, green means a new roof installed with attention paid to emissivity - the degree to which the roof reflects heat and sunlight away from the building - reduced energy consumption, and the recycling of tear-off materials. Different products, different practices. Once incorporated into a company's procedures, customers are often open to these. But cost remains an issue, and not all homeowners are open to green roofing or green roofing products.

Roofers who attend trade shows and read trade magazines may know about green roofing products, but homeowners generally know little. "It hasn't taken off like it has in commercial," says Chris Kamis, owner of Absolute Roofing & Construction, in Parma, Ohio, which divides its business about evenly between commercial and residential jobs. Other companies find similar.

"The customer never brings it up," notes Brett Hall, president of Joe Hall Roofing, a Pantego, Texas, company that also does both commercial and residential roofs. Hall says that it's up to him to introduce homeowners to the subject of cooling the roof with enhanced ventilation and different shingle colors. And if people are getting a new roof because they're planning to move, as is often the case, "it's not that popular a subject. Why invest in something when they can never recoup the cost?"