Mr. Nall is a professional engineer, an ASHRAE and an AIA Fellow, a LEED Fellow, an ASHRAE certified Building Energy Modeling Professional, a certified High Performance Building Design Professional and a Certified Passive House Consultant. He has been involved in building energy efficiency and HVAC engineering for 45 years. Buildings in New York City for which he has a substantial role in the engineering design include the New York times Headquarters, 200 West Street, 150 Charles Street and the Hearst Corporation Headquarters Tower. He has been a faculty member at the Schools of Architecture at the University of Pennsylvania, Princeton University, Cornell University and Columbia University. He has been involved in energy efficiency and sustainability in buildings for over 40 years and is the author of numerous papers in professional and technical journals. He has also presented at numerous USGBC, AIA and ASHRAE national conferences and conventions, and at international events in Spain, Italy, Brazil, Argentina, UAE, India, and Indonesia.