By Jim Carlton

Las Vegas

Two more housing developments are set to open in this booming desert metropolis next month, but they will feature a competitive twist: use of what the builder calls "earth-friendly features" such as recycled carpets and porous driveways that let rainwater seep back into the soil.

The Ventana and Aliso subdivisions being built by Pardee Homes are part of a green-building trend that has spread to the nation's housing tracts. During the past decade, environmentally friendly building practices have become increasingly common in custom housing. But now, spurred by the economics of greater energy efficiency and pressured by environmentalists, residential builders of all kinds are embracing green standards in everything from materials to design.

Officials of Pardee Homes, a Los Angeles-based unit of timber-giant Weyerhaeuser Co., say that over the past year they have also opened two green subdivisions in San Diego after seeing the demand for saving on energy bills. By using fluorescent lighting and a (solar power system)..., they say, they have been able to achieve energy savings of as much as 75% compared with conventional homes. They add that local environmental groups helped persuade them to take land-preservation measures such as replanting trees and plants.

Homes in the San Diego subdivisions, priced from $500,000 to more than $1 million, have been selling briskly, Pardee officials say, and they plan to gradually increase their green offerings. "We see this as just the beginning of our green-building program," says Joyce Mason, vice president of marketing for Pardee, which builds about 2,200 single-family houses a year.

The trend is still relatively small, but growing fast. Officials at the National Association of Home Builders, a big trade group in Washington, D.C., say that about 13,000 of the 18,000 homes that have been built over the past decade in accordance with their group's green specifications were constructed last year. Meanwhile, a 2001 survey by Cahners Residential Group, an industry trade publisher, found that 28% of 344 U.S. builders questioned in a survey used green techniques on most of their developments. That was an increase from 22% when the survey was conducted in 2000. In the same 2001 survey, 94% of 300 American consumers questioned cited energy savings as their most sought-after green upgrade, followed by majority preferences for water-saving appliances and recycled building materials.

"What's happened is that over the past quarter century, the environmental awareness in this country has rocketed off the charts," says John Kurowski, a small builder from Littleton, Colo., who pioneered green-building methods like the use of solar power in the 1970's.

Industry groups have set up programs to encourage green building in 18 locales nationwide, with five more set to follow soon. Programs are already in place, for example, in Atlanta, Denver, Seattle and the state of California. Last year in California, industry officials say, about 540 homes were built to follow program standards such as reducing water consumption by 25% and construction waste by 50%. Another 750 are expected to be built in 2003.

. Green building isn't for everyone. Many building suppliers say the demand for green products is being driven more by environmental groups than the general public. "What you need for the green movement to really be successful in building is for all the homeowners to want it, but that's just not the case right now," says Jim Rush, a marketing vice president for Temple-Inland Inc., an Austin, Texas, supplier of wood products.

Builders say that in many cases another impediment is local zoning laws. A builder in Texas was told his plan to construct narrower streets - so as to preserve trees and increase natural water runoff - couldn't be approved because the law required standard, wide streets. But builders add that increasingly municipalities are becoming so enamored of the final result that they are waiving certain rules and even expediting the permit process for green projects.

"We've decided that building green is the right thing to do," says Joan Kelsch, an environmental planner in suburban Arlington County, Va. This summer the county is scheduled to roll out a program of rewarding home developers who use green techniques by fast-tracking their permits and inspections.

At the International Builders Show in Las Vegas last month, green building was one of the subthemes of a convention that attracted some 90,000 builders from all over the world. There were panel discussions on the trend, as well as numerous green products on display. Temple-Inland showcased some gypsum wallboard made from at least 95% recycled materials, while Swiss agribusiness giant Syngenta AG demonstrated a greener termite barrier. The so-called Impasse Termite System is designed to encase insecticide inside a plastic sheet beneath a home's foundation so that the chemical doesn't have to be sprayed outside and left to seep into the ground.

The economic benefits of green building first became apparent to some builders more than a decade ago. Builder Michael Rose opened his Northridge development - featuring a park-like setting of a lake and old trees - in Maryland's Prince George's County in the early 1990s, just as the local housing market was cratering. "We had oodles of competition," Mr. Rose recalls, yet his 855 homes sold briskly.

At about the same time in Houston, Emerald Homes had begun testing new energy-efficient designs. The builder, now owned by D.R. Horton Inc. of Arlington, Texas, had begun outfitting its homes with such amenities as double-paned windows and glass designed to cut down on sunlight in the late 1980s. As a result, energy consumption in these homes was about 50% lower - saving customers on average $150 a month on their electricity bills in the sweltering Houston climate, and more than offsetting the added building cost of as much as $4000 a home. Now all 650 of the homes the builder constructs annually in the Houston area use these and other green features.

"Nobody said we had to do this," says Brian Binash, Emerald's president. "It was just something we saw the marketplace wanted."

Industry officials say demand for more energy-efficient homes took off in 1994 after the U.S. Environmental Protection Agency launched its Energy Star program, which rewards homeowners with rebates and other incentives for using less energy. Since then, about 100,000 homes nationally have been built to the Energy Star standards. Builders say interest in energy efficiency - and ancillary green-building techniques - has accelerated since the run-up in power prices two years ago across the West and other parts of the country.

"Being a developer has been a bad word," says Steven Lewis, a green builder from Atkinson, N.H. "But people need to understand there are good builders and bad builders, and many of us are trying to do the right thing."