Paul Byard began his career as a lawyer at Winthrop & Stimson, and worked for the New York State Urban Development Corporation to develop public housing. In 1977, Byard received his Master of Architecture at Columbia University, Graduate School of Architecture, Planning and Preservation. During his graduate studies, Byard supported the legal defense of the New York City Landmarks Preservation Law. The work culminated in 1978 when the US Supreme Court decision in the Penn Central Transportation Co. vs. The City of New York upheld the constitutionality of historic preservation laws. From 1968 to 1989, while serving on the board of the Municipal Art Society, Byard was the primary author of briefs amicus curiae that helped facilitate the security of the New York Landmarks Law during the Supreme Court Case that saved Grand Central Station.

Paul Byard joined the James Stewart Polshek & Partners architecture firm, and was made a partner in 1981. In 1989, Byard joined Charles A. Platt Partners (later known as Platt Byard Dovell White). He brought his legal experience to Columbia’s Historic Preservation Program by teaching a Preservation Law class. His book, The Architecture of Additions: Design and Regulation, was published in 1998, as a critical review of architectural additions as a creative paradigm, and more specifically, “what ought to happen when architecture is added to distinguished buildings protected by law”. In 2000, Paul Byard was appointed Director of the Historic Preservation Program at Columbia, where he served until his death in 2008.