State Superintendent Tom Torlakson gave all the details at the Pasadena Civic Auditorium Monday.
Seventy-one percent of schools in California are 25 years or older, and the age of the buildings is starting to show.
In addition, school districts pay hundreds of thousands of dollars a year in energy costs.
Torlakson and environmental advocates want that changed by modernizing the state's schools.
The idea is that newer buildings are less expensive to operate than structures built 50 years ago.
"It costs a lot less to operate this building [the Pasadena Civic Auditorium], and people can learn a lot better in this building than they can in most of the public schools here in Pasadena or anywhere else in California," said Sierra Club Chairman Carl Pope.
According to the BlueGreen Alliance, high-performance "green" schools can use 33 percent less energy and 32 percent less water than other schools.
At Monday's conference, Torlakson pushed for support for the American Jobs Act to modernize state schools.
"The American Jobs Act has $2.8 billion for California that could be used just for this very purpose," said Torlakson.
Modernizing schools and making them "green" will also create new jobs.
"For every billion dollars we spend on school construction of the type we just discussed, we create 10,000 jobs," said Torlakson.
Environmental advocates say starting with the buildings used to educate kids is a step in the right direction.
"We'll modernize our schools if we'll make them just as good as the buildings we're building now for businesses. We'll have happier kids, healthier kids, better-educated kids and cheaper tax rates," said Pope.