Complex sentence: Library II, a four-story addition, opened in 1990, adding 88,000 assignable square-feet and included the installation of a large compact storage unit in the Library I lower level for enhanced collection space.
Split into simpler sentences: Library II, a 4-story addition, opened in 1990. This added 88,000 assignable square feet and included the installation of a large compact storage unit in the Library I lower level for enhanced collection space.