Gregory Dietrich is a sole proprietor located in Manhattan and exceeds Professional Qualification Standards for Architectural History as set forth in the Code of Federal Regulations, 36 CFR Part 61.

A graduate of Columbia University's Historic Preservation and Real Estate Development programs, Gregory Dietrich has worked in the field of Historic Preservation for over 20 years. Between 1999 and 2000 he served as the Acting Director of the New York City Landmarks Preservation Commission's Historic Preservation Grant Program before undertaking the National Register Nomination of Lincoln Center in 2001. In 2002 he joined Cultural Resource Consulting Group (CRCG), where he managed the New York office starting in 2004. At CRCG, he was a project manager and principal investigator on numerous cultural resource studies to satisfy state and federal regulatory permitting requirements that included many types of historic architectural and landscape analyses. In 2009 he established Gregory Dietrich Preservation Consulting, focusing on National Register Nominations, historic tax credit applications, grant applications, preservation planning studies and client representation. In addition to his private clientele, he consults to three municipalities in the New York metropolitan area, and has appeared before planning boards and preservation commissions in New York, New Jersey, and Connecticut, offering expert review and testimony. Since 2018 he has served as an adjunct instructor in the Art History, Urban Design and Architecture Studies program at New York University's College of Arts and Sciences.