The Foxborough Regional Charter School soon will celebrate not having modular classrooms.

A Jan. 21 ribbon-cutting ceremony and open house will mark the completion of a $17.7 million facilities expansion project, school officials said today in a press release. The event is from 10 a.m. to noon.

The project includes a 27-classroom middle and high school addition that is replacing the K-12 school's 26 modular classrooms, Executive Director Mark Logan has said.

The charter school has had modular classrooms since 2004, adding more since then.

The school serves about 1,200 students from 20 area communities: Attleboro, Avon, Brockton, Canton, Easton, Foxborough, Mansfield, Medfield, Medway, Millis, Norfolk, North Attleboro, Norton, Norwood, Plainville, Sharon, Stoughton, Walpole, West Bridgewater and Wrentham.