Charles R. Zimmerman is currently the vice-president of Prototype and New Format Development for Wal-Mart Stores, Inc. Mr. Zimmerman is also leading the "Sustainable Buildings Network" at Wal-Mart. This network, among other things, is charged with increasing the overall energy efficiency of new and existing buildings by 20-30 percent. Prior to his current role, Mr. Zimmerman worked in the International Division for Wal-Mart Stores as Director of Design and Construction. Mr. Zimmerman has worked for Wal-Mart since 1997. Previously, he worked in both the consulting industry as well as for the Texas State Department of Highways. Mr. Zimmerman is a graduate of the University of Arkansas, a registered professional engineer, and member of the Arkansas Academy of Civil Engineers.