AURORA, Colo. – Rows of little plastic domes dot the roof of the new Wal-Mart Supercenter here, looking like a marching band of "Star Wars" R2-D2s.

Inside each dome, a trio of computer-aimed mirrors tracks the sun and bounces its light down a reflective shaft and through a milky white lens, illuminating the stockroom below.

FILE 2005/DMN

Solar panels are one environmentally friendly feature at TI’s semiconductor manufacturing complex.

The skylight idea is centuries old. But the mirrors, the lenses and dozens of other energy- and environment-saving innovations are new, and they're showing up not just at Wal-Mart Stores Inc. but at other companies, schools and public agencies.

In addition to the Wal-Mart's legion of skylights, for example, the store's foundation is made of ground-up chunks of runway recycled from Denver's old Stapleton International Airport. Porous paving in its parking lot soaks up and filters polluted storm-water runoff. Huge north-facing windows provide most of the store's interior light. Used motor oil from the tire and lube shop helps heat the store, as does old vegetable oil from the deli.

According to Don Moseley, senior Wal-Mart engineer for environmental innovation, these and other efforts "are good for the environment and good for our business."

That's the mantra of the so-called green building movement that's sweeping the nation. Among the adherents are financial institutions such as Citigroup, PNC and Bank of America; automakers such as Toyota, General Motors, Ford and Honda; and such retailers as Wal-Mart, Target, Home Depot, Lowe's, Chipotle and Patagonia.

The next two new Major League Baseball parks, in Minneapolis and Washington, D.C., are poised to go green. So is the biggest privately financed development under way in the United States: MGM Mirage's $7 billion Las Vegas City Center, due in 2009.

Future federal buildings will be green, too. The General Services Administration, the nation's biggest landlord, announced last spring that it was applying stringent green-building standards to its $12 billion construction portfolio of courthouses, post offices, border stations and other buildings.

FILE 2005/AP

Several green buildings have been going up in North Texas, including a Wal-Mart in McKinney that has skylights and native landscaping.

The key to the movement is a new set of standards that's far more demanding, environmentally speaking, than local building codes. The movement invites innovation because it's based on environment-protecting performance standards, not rules. That leaves it up to architects, builders and designers to decide how best to reduce energy and water consumption, for example, or workers' dependence on cars.

The U.S. Green Building Council, a Washington, D.C.-based alliance of some 7,200 architects, builders, land use planners and academics, issued the first set of standards in 2000, covering big commercial construction projects. Standards for existing buildings and commercial interiors came out in 2004. Criteria for new single-family homes, public schools, hospitals and cookie-cutter commercial buildings such as bank and retail store branches will come in the next year or two.

The council's goal is to "transform the marketplace" in real estate in the United States and globally, said Rick Fedrizzi, the council's founding chairman and chief executive officer. "We'll be at that point" in the movement, Mr. Fedrizzi said recently, "when it's no longer called green building; it's just the way building is done and they are simply called buildings."

In fact, council-certified green buildings have been spreading like wildfire since 2000. In that year, about $790 million in new commercial construction met the council's standards. This year, about $7.2 billion does. In 2000, a few hundred projects sought council approval. Today, more than 4,900 have registered for certification.

It's easy to imagine a green building rout in the next few years, based on the virtually unchallenged logic that buildings in an era of global warming need to be designed to minimize their environmental impact. Already, some retailers, such as Patagonia and Chipotle, are marketing their greenness as an attribute that sets them apart from competitors.

That's likely to accelerate with the council's upcoming release of a performance-rating system for generic store designs that retailers such as Starbucks and Whole Foods rely on for their new construction nationwide. If the council influences those portfolios, thousands of green buildings will start popping up across the country at viral speed.

"A lot of us think retail is the tipping point," said Kim Hosken, the council's director for new construction.

Headwinds of resistance to the movement are building.

For one thing, building green, at least until recently, was presumed to cost more upfront but to pay off in the long run through lower operating expenses.

"You will spend more on insulation and windows," said Glenn Munro, a Toronto-based retail shopping-center developer. "But you'll save on electrical costs by downsizing the air-conditioning and heating systems and so on."

That takes patience. Governments and universities have it because they tend to own their buildings and keep them for generations. For the same reason, retailers such as Wal-Mart, Home Depot and Target, which generally own their real estate, find it relatively easy to go green.

But for retailers such as T J Maxx, Pottery Barn and legions of others who lease their properties, there's little to gain from greening. Any savings on properties that they lease generally would go to landlords. And landlords, who often own properties only briefly and do business in highly competitive markets, will be hard to excite about green building.

A variant of that problem arises with new-home buyers, said Michele Myers, a custom-home builder in the Durham, N.C., area. Whatever the long-term savings on heating and cooling bills, she said, buyers rarely choose to spend more upfront on energy-efficient appliances and extra insulation.

"The paybacks are too far down the road for most people," Ms. Myers said. "LEED may be great, but it's for the affluent, not the majority of Americans out there."

But that may be changing.

The added costs of green building – long assumed to be 10 percent to 20 percent more than traditional construction – are falling and may have been exaggerated, according to some who've built green recently.

"There's an assumption of a green premium, but we haven't found that," said Jeffrey Smith, Harvard's director of facilities maintenance.

Mr. Smith's greatest surprise, he said in an interview, was "how interested building occupants are in these projects. It's almost as though they're looking for something they can believe in."

Here are some recent environmentally friendly projects in North Texas.

• Pat Lobb Toyota and Scion in McKinney opened a $7 million building this year filled with recycled materials. Its carpet is made from corn, and the dealership plans to use old motor oil to heat its shop during cool weather.

The dealership's carwash system is designed to recycle rinse water, saving about two-thirds of the water normally lost each time a car is cleaned.

• Southern Methodist University's new $16 million engineering building uses recycled water from the air-conditioning system to irrigate landscaping. Flushless urinals save water. The school also uses larger windows to rely more on natural light.

Officials at SMU expect to save about $70,000 in energy costs annually.

• Wal-Mart Stores Inc. opened an experimental "green" store in the summer of 2005 in McKinney, featuring a 120-foot windmill and solar panels to generate energy to light the store's signs.

Native landscaping is designed to rely on less water, and flowerbeds use a drip-irrigation system rather than sprinklers.

• Dallas-based Texas Instruments Inc. began building a semiconductor manufacturing complex in Richardson in 2004 that boasts several environmentally friendly features such as solar water heating, reflective roofing, use of recycled materials, a rainwater storage pond and native landscaping.

• Sabre Holdings Corp.'s Southlake headquarters, which opened in 2002, uses rainwater to keep the landscape green and doesn't use pesticides. New wetlands and native grasses were also introduced to the campus.

Interior lighting is designed to take advantage of natural light. Employees recycle about 96 tons of paper, plastic and aluminum annually.

Suzanne Marta/DMN