More than half of the Butler buildings have green roofs planted with 14 sedum varieties.

The Princeton University Campus Plan and Sustainability Plan, both completed in 2008, focus on improvements in infrastructure, transportation and open spaces. The mantra for campus development is, not surprisingly, sustainable growth. This means sustainable building design, expanded landscaping and reforestation, stream restoration, increased conservation and recycling, and improved water management.

Under the aegis of the Princeton Environmental Institute, studies will to be conducted over the next few years to allow researchers to collect data on how much energy is being conserved by the buildings?EUR??,,????'?????<