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.

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 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.

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, 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.