William B. Warfel, an architectural and stage lighting and equipment developer, established a private practice in 1971 and in 1998, with Sara Schrager, formed Warfel Schrager Architectural Lighting, LLC; in 2007 he left WSAL and continued in a new firm, William B. Warfel Lighting and Theater Design. He has done international consulting work on over sixty theatre construction and renovation projects. His lighting designs have been used in numerous commercial buildings, large public structures, bridges and houses of worship. Theatre and other entertainment lighting design work has taken Warfel throughout the United States as well as to Ecuador, Nigeria, and Finland. He has also addressed both academic and professional groups in China, Egypt, Finland, Iceland, and Sweden as well as the United States.
William Warfel is the author of several books and a computer program dealing with stage lighting. He is a graduate of Yale University and Yale School of Drama. He has taught stage lighting at Dartmouth College and Long Island University and is on the faculty of Yale School of Drama as Professor Emeritus in the Design Department.