The Bannan biology building was built in 1989 with a green roof.  The roof was planted with five feet of soil that supports many large pine trees.  The building was built into the hillside making the green roof accessible from the adjacent quad. Skylights in the green roof bring daylight into the space below.  The roof structure is made of concrete honey comb, R-27 rigid insulation, water proof membrane and filter fabric.  Once the plants are saturated, the extra rain water overflow drains to the storm sewer.  The soil mix is 70% sand and 30% mulch.