As baby boomer-era school buildings become more and more outdated, many districts are building green schools to replace energy guzzling, polluted learning environments.

School construction is big business -- it makes up 27 percent of the US construction market. Building a school that complies with LEED standards costs 2 percent (or $3 per square foot) more upfront, but it's worth it -- green schools use up to 30 percent less energy, 30 to 50 percent less water, and reduce carbon dioxide emissions by 40 percent compared to traditionally built schools.

Green schools can help make students healthier too. As many as 15,000 schools have poor indoor air quality that triggers asthma, causes headaches, and spreads airborne illness, especially among children, who breathe more air, proportionally, than adults.

There's also evidence that green schools help educators teach and students learn. In a 2005 survey of executives that planned and built green K-12 schools, 71 percent said that students performed better and 72 percent said that there was less absenteeism compared to other schools.