WATERVILLE — Colby College’s expanded art museum is opening this weekend.

The museum has been closed while workers completed an addition that means the museum now has 38,000 square feet of exhibition space, the largest in the state.

A “friends of the museum” event on Saturday on campus in Waterville will be followed by a formal opening to the public on Sunday.

The college hopes that the new and improved museum will lift the state’s profile as an art destination.

The addition became necessary after Peter and Paula Lunder donated about 500 works from their private collection to the museum. The Alfond-Lunder Family Pavilion adds 10,000 square feet of exhibition space and serves as the museum’s entrance.