As seen in the Christian Science Monitor.

Clearview Elementary in Hanover, Pa., is a myth buster in how to build green. A wall that filters the sun helps reduce energy use by 38 percent, but here's the more amazing thing: Clearview cost virtually the same to build as a conventional school (1.3 percent more). Cost is not the barrier to energy-savvy construction that people think.

Buildings of all kinds use three-quarters of America's electricity. Schools, whose hallways enfold almost everyone at some point, are a good place to focus on lightening America's energy footprint. And as places of learning, they can train up millions of students to think as naturally about conserving as they do about text-messaging.

The most common barrier to building green schools is a misconception about costs and benefits, reinforced at a time of drought in state and local revenues.

A 2006 study put out by the US Green Building Council can wash away those concerns. (The council is the nonprofit that developed the nation's premier standard for environmental construction, known as LEED.) Its study of 30 green schools nationwide shows that the initial building cost is only slightly higher than the outlay for traditional schools – by an average of 1.65 percent, though one school went over by more than 6 percent. The difference, though, is quickly made up and turns into serious savings through reduced energy use and improved learning conditions.

Garden roofs, solar panels, and low-flow sinks helped cut energy and water use in these schools by a third. Recycling knocked down solid waste by three-quarters. Lots of natural light and smart ventilation and good acoustics aid student concentration and reduce absenteeism and teacher turnover.

The buildings themselves become teaching tools for hands-on science. At Clearview, completed in 2002, the sun-screen wall doubles as a sundial. At Tarkington School for Excellence on Chicago's South Side, the rooftop garden serves as a lab. In April, eighth-graders gave expert tours of the building, explaining its architectural and environmental benefits.

Colleges and universities are leading the way in educational greening, though sometimes it's more show than substance. Still, it's easier for a college president to change direction than for the many stakeholders and decisionmakers in public schools.

But now they, too, are moving, spurred in part by the Green Building Council, which introduced LEED standards for K-12 schools last year. Nationwide, about 1,000 schools, both public and private, meet LEED standards or are in the pipeline to meet them – and schools are applying at a rate of more than one a day. Eight states, from Maryland to Hawaii, require new schools to be built green, and Pennsylvania and California offer strong incentives. As more public officials learn about green schools, they should set their sights even higher – retrofitting existing schools (there are 126,000 of them); building in high-density areas so kids can walk or bike to school; and linking their facilities to other buildings through shared local renewable energy. And, as more architects and suppliers use green technology, the cost of environmental building will continue to drop. The sky's the limit – as well as the source.