Complex sentence: Originally slated to be opened in January 2006, construction was far enough along to allow the 2005-06 school year to start in the new structure while construction continued on-site until the spring of 2006.
Split into simpler sentences: Originally slated to be opened in January 2006, construction was far enough along to allow the 2005-06 school year to start in the new structure. Construction continued on-site until the spring of 2006.