Glenbard West High School unveiled a classroom addition Thursday night with tours and student demonstrations.

During an open house, families and other visitors were greeted by innovative science labs on par with those of colleges, teachers at the Glen Ellyn school say.

Students have been taking physics and chemistry classes in the 28,000-square-foot addition since the start of the school year. But on Thursday, residents got a behind-the-scenes look at how teens will use the spaces and a “green” roof above the addition overlooking Lake Ellyn.

Glenbard High School District 87 broke ground more than a year ago on the addition — the first to the original building since 1963.

The addition and renovation of former science classrooms cost about $10.5 million. Mechanical, electrical and plumbing work for the addition totaled another $4.5 million.

West also now has a schoolwide, air-conditioning system that was installed over the summer. Building a cooling plant cost roughly $1.3 million.

The addition was funded in part through a $35 million tax-backed loan approved by voters in March 2014.