Complex sentence: Renovations were completed in March 2003, which feature a 16,000-square-foot air-conditioned glass-enclosed atrium built on the northwest side of the arena, to keep patrons cool while waiting in line for tickets or spending time inside the building before events.
Split into simpler sentences: Renovations were completed in March 2003, where it features a 16,000-square foot air-conditioned glass-enclosed atrium built on the northwest side of the arena. It is to keep patrons cool while waiting in line for tickets or spending time inside the building before events.