Paul Torcellini is a Principal Engineer for commercial buildings research at the National Renewable Energy Laboratory (NREL), a DOE laboratory and he is on the faculty at Eastern Connecticut State University. Paul is a key contributor in the development of the Advanced Energy Design Guides (ASHRAE/AIA/IES/USGBC) including chairing the technical committees that produce the zero energy AEDGs. Paul has been at NREL for 29 years and is a registered Professional Engineer holding a PhD from Purdue University as well as an ASHRAE Fellow and Distinguished Lecturer. Paul has authored or co-authored more than 50 papers and articles related to energy efficiency and zero-energy commercial buildings.