When Zurrell Toney met Michelle Obama, the talk was all about "green."

"Well, first my jaw dropped when I saw her walk through the door," said Toney, 19, who was one of 18 students from YouthBuild Philadelphia Charter School helping to assemble a demonstration house Tuesday on the National Mall in Washington when the first lady showed up.

Toney regained his composure, however, and was the first student to walk up to Obama. He began talking about "finger-jointed studs" - 2-by-4s engineered from waste lumber and used to frame the house "so we don't have to cut down more trees."

In a year, Toney has gone from high school dropout to a guy who can talk sustainable building with the president's wife, giving full credit to the "life-changing experience" of the 12-year-old North Philadelphia charter school, which has more than 200 students from low- and moderate-income families and is funded with a variety of public and private grants.

When he graduates Aug. 28, he will head to Thaddeus Stevens College of Technology in Lancaster, then to Community College of Philadelphia to study business.

Just as YouthBuild has changed Toney and given him a path to a better future, sustainable or green building is changing the way the school, and the national organization of which it is a part, views and teaches construction.

"The emphasis on green building is growing," said Amy Kapp, the school's public-relations coordinator, who accompanied the students to Washington, as they and 150 other YouthBuild students created the "green" house.

"We have changed our curriculum to include green techniques," said the school's executive director, Simran Sidhu, "and as new elements emerge in green building, and we find out what those are, we will continue to adapt our training to include them."

Sidhu is hoping to align the school's science curriculum to green initiatives, "so that students learn the principles and science behind greening as they learn to build green."

The Philadelphia students created the package of framing material for the demonstration house, which, after being set up Tuesday, was disassembled and shipped to Texas for completion as a home for a low-income family.

Green techniques - paperless drywall, renewable energy, spray-foam insulation, and recycled lumber, to name a very few - are fast becoming an integral part of residential building and remodeling.

"Green building is the future of home building," said Eric Borsting, chairman of the green building subcommittee of the National Association of Homebuilders.

"It's noticeable in the availability of materials - the price of renewable energy products and appliances, like photovoltaic panels, is coming down," while other products, such as paints with no or low volatile organic compounds, "no longer have to be special-ordered," he said.

YouthBuild's construction students - the school offers technology and nursing courses as well - are using many of the techniques and products as they work on six projects - three for Resources for Human Development, one for the Nicetown Community Development Corp., and two for churches.

"In the fall, we'll start a Nicetown house that will integrate completely green techniques," Kapp said.

Seven to 12 students work on a project a time, with those not doing hands-on tasks busy in the classroom, Kapp said.

The school encourages its students to continue their education; 50 percent head off to two- to four-year schools afterward. Thirty percent enter the workforce, and YouthBuild helps them find jobs, even in today's tough employment market.

Training in sustainable building techniques is a plus.

"An increasing number of builders are obtaining green certification, making it a bright spot even in the middle of this downturn," the NAHB's Borsting said.