The green house effect: eco-friendly design grows more practical and more acceptable

So much for our nation's red and blue recent past. America is turning green, and the change is only partly related to politics. If you looked at a time-release map of the United States over the past five years, you would see the color seeping across the country, as environmentally-friendly building has become more desirable and more doable--no longer a buzzword but the bedrock of sound design and construction. The sea change started in the late 1990s, with the U.S. Green Building Council's system for rating the environmental impact of commercial buildings, and now sustainability is tugging the residential tributary toward the mainstream as well.

Two decades ago, green design was an oxymoron, a fringe movement that was narrowly focused and produced buildings that were often uninspiring. More recently, it was seen as a luxury for those who could afford to tinker with building-integrated photovoltaics and fancy air filtration systems. Theoretically, private clients wanted a resource-and energy-efficient home, but they didn't know how to ask for it, and they certainly didn't want to pay more for it. Architects didn't understand it either, at least not in any sophisticated way. That is changing measurably, driven by several far-reaching developments.

It's been five years since the USGBC's Leadership in Energy and Environmental Design (LEED) rating system took effect, giving commercial developers a rigorous way of determining whether or not a building had good environmental performance. "My sense is that there's been a dramatic leap in interest in sustainability and in the knowledge of it," says Alex Wilson, president of BuildingGreen, Brattleboro, Vt. "The number of LEED-accredited professionals has increased from 8,000 a year ago to 19,000 today." The new LEED Home certification program, slated to be applied around the country in 2006, will push residential architecture in the same direction.

Huge advancements in mainstream building products have also allowed residential architects to spec green with greater confidence. Wilson notes that the use of high-performance glazing, such as low-E coatings and glass filled with argon and krypton gas, now represents half the market of window manufacturers such as Andersen and Marvin. Paints, sealants, and adhesives have stepped into the ecologically aware 21st century too. "Emissions of harmful chemicals have dropped tremendously in the last five years," Wilson says. "Paint products have become much greener, without a significant change in price. Now we have mainstream manufacturers offering products with zero volatile organic compounds, and very-low-VOC products that exceed even the toughest standards in California." Cabinet manufacturers have begun to change their toxic ways too, by offering formaldehyde-free kitchen cupboards.

eco-conundrum

As encouraging as that trend is, it will be some time before eco-specs become second nature. Fortunately, there are a growing number of online resources architects can turn to for help in determining a construction method's or a material's shade of green. Perhaps the best-known arbiter of green products is the 5-year-old GreenSpec Directory, updated each year by BuildingGreen (www.buildinggreen.com).

So what does make a product true-green? In some categories, green is quantified by establishing thresholds for what the directory's editors want to measure. For example, they won't consider a paint with more than 50 grams of VOCs per liter. "We want to list just the greenest products, so we're aiming for the top 5 percent to 10 percent of products," Wilson says. "As a result, we change our criteria constantly. When we look at all paints, we find that 95 percent have VOC levels higher than 50 grams per liter, so we set a threshold at 50 grams."

Products that consume energy are fairly easy to evaluate too, by setting a standard for performance. Most of the energy consumed by clothes washers, for example, is used to heat the water, so as water consumption drops, energy performance rises. "Since we started the directory, we've dramatically tightened those standards," Wilson says. "Today, only front-loading or horizontal-axis and the very best vertical-axis washers meet those criteria. The energy cycle has to do with the amount of water extraction, too, which affects how much energy it takes to dry the clothes." To evaluate wood products, the editors rely on certification from the Forest Stewardship Council, an independent nonprofit group. They also set standards for recycled content on certain materials. "We look at what's out there, what's achievable, and what's reasonable," Wilson says.

Even with the help of vetted lists, choosing materials and products based on their environmental impact is like comparing apples to oranges, trying to weigh a material's harvesting practices against the manufacturing process, how far it must be shipped, and the effects on indoor air quality. Of course, green design has a hierarchy. Energy performance trumps recycled materials, for example. "A lot more resources get used on energy to heat and cool a house over its lifetime than on the materials to says Henry Siegel, FAIA, Siegel & Strain Architects, Berkeley, Calif. And, given the choice, durability is more important than embodied energy. Recycled content also warrants close scrutiny. "A lot of recycled materials have nasty stuff in them," Siegel says. "We avoid things that use vinyl, formaldehyde, and other known carcinogens. Green-Spec tells you a lot, but sometimes we'll ask manufacturers for material safety data sheets, and if we don't know what an ingredient is, we'll call and ask."