Susan K. Weiler, Fasla, is a partner at OLIN, a landscape architecture and urban design firm based in Philadelphia, Pennsylvania. She lectures widely and teaches landscape architecture at Temple University, where she developed its landscape engineering and construction curriculum. She is the recipient of the 2003 Green Roof Award of Excellence.

Katrin Scholz-Barth is a consultant from Washington, D.C., currently working to help establish green roofs in the Middle East. A national expert in green roof technology, she leads efforts in ecological planning and design both in the United States and the Middle East. She taught at Harvard University and the University of Pennsylvania and is former director of sustainable design for the HOK Planning Group, a business unit of The HOK Group, Inc. She is also the recipient of the 2003 Green Roof Award of Excellence.