Complex sentence: Chapin School built a new pre-school and kindergarten building, the Margaret Wilby Primary Building, replacing the old Pre-K building during the 2006-2007 school year.
Split into simpler sentences: Chapin School built a new pre-school and kindergarten building, the Margaret Wilby Primary Building, replacing the old Pre-K building. The structure was finished during the 2006-2007 school year.