There's little use for the light switch in the library anymore — sunlight has nearly replaced overhead lights during the day.

That means gloomy winter days may not seem so dark this year at Ben Franklin Elementary School, thanks to the new school's environmentally friendly design, said Peggy Anderson, the school's librarian.

"It feels bright and light and open here," Anderson said. "You can feel air movement. The kids love it here."

Ben Franklin Elementary in Kirkland opened this school year as one of the newest schools to be constructed under the state's "green school" standards.

Other districts, including Seattle, Northshore and Arlington, also are using elements of the green standards in new construction.

Ben Franklin, of the Lake Washington School District (LWSD), was designed to be more environmentally friendly, using natural light and ventilation and natural materials such as rubber and wool.

"It's a beautiful building," said Superintendent Don Saul. "More impressive than when I saw a model of it sitting on my conference table."

The school cost $9.8 million to build, about the same price as for a conventional school, said Kathryn Reith, spokeswoman for the district. The new building is at least 35 percent more energy efficient than the old one and will save 40,000 gallons of water yearly by using waterless urinals.

"It's very different than the old school," said the principal, Mary Cronin. "Some of the parents have said the school looks like Barnes & Noble."

The new school has carbon-dioxide monitors in each classroom that trigger louvers, which let in fresh air to keep students and teachers from feeling drowsy. Overhead lights dim when the natural light is bright enough, and motion sensors turn the lights off when the room isn't in use.

Windows facing south are shaded to keep the light from causing glare in the room, and the light is diffused and bounced farther back into the rooms with the help of light shelves.

The school is an example of a trend toward using sustainable resources in school construction. These new, environmentally friendly school designs will become standard for public schools seeking state matching funds for construction beginning in 2007.

Northshore School District's Cottage Lake Elementary School opened its doors this year after reconstructing part of the school to meet the green standards. Cottage Lake's design includes many of the same elements as Ben Franklin, including outside air ventilation and better use of water runoff.

Cottage Lake Principal Karol Pulliam said teachers are still getting used to the new building.

"We're used to being in sealed buildings, where we don't get fresh air," Pulliam said. "They feel cool air coming in and may think something is wrong with the heater, but it's just the building letting in fresh air."

Greenwood Elementary School in Seattle also incorporates elements of green school design, said Peter Daniels, spokesman for Seattle Public Schools. The school opened in 2002 and uses natural lighting and natural ventilation.

"It's good Earth stewardship, and good stewardship over our own public-resource dollars," Daniels said.

Arlington School District has built several schools in recent years using an energy-efficient design incorporating natural lighting, said Warren Hopkins, assistant district superintendent.

Ben Franklin Elementary's design even celebrates the rain through rock fountains that are fed from water runoff, said Forrest Miller, LWSD director of support services. Excess runoff is filtered through beds of dirt over pieces of glass; the bits of glass remove debris much the way pea gravel would and allow some of the water to seep back into the earth. The glass is recycled from a Woodinville glass studio.

"It cost less than regular gravel," Miller said. "The studio would have had to pay to get rid of it. All we had to do was pay to haul it here."

Rachel Tuinstra: 206-515-5637 or rtuinstra@seattletimes.com