Before-and-after images show how an abandoned Kmart was transformed into a high school

For years, the Kmart in the Chicago suburb of Waukegan, Illinois sat abandoned, except for squatters who had moved in.

But now, high school students fill its halls, library, and cafeteria — once store aisles and space for checkout lines. 

The former Kmart is the new home for Cristo Rey St. Martin College Prep, which was recently redesigned by the local design firm JGMA. The team of architects transformed the dingy store into a bright facility, complete with all the amenities of a modern high school.

Business Insider spoke with Juan Moreno, the founder and president of JGMA, about the project. Take a look below.

Until the store closed in 2013, it was the only Kmart in Waukegan. Here's what it looked like before the redevelopment:

The building is now the home of Cristo Rey St. Martin College Prep, which serves nearly 400 low-income, mostly minority students.

Cristo Rey is a national network of 32 schools. The one in Waukegan (before it moved into the former Kmart) opened in 2004 and has a 98% college-enrollment rate.

The empty store was challenging to convert, because the firm wanted to keep to a relatively low budget of $10 million, Moreno told Business Insider.