The Byron G. Rogers (BGR) Federal Office Building, just under 500,000 sq ft and located in downtown Denver, is pursuing impressive sustainability targets above and beyond federal requirements. Built in the 1960s, this building not only has to achieve federal 2030 NetZero goals, but as a historic building it must also reflect respectfully on its past and preserve architectural elements characteristic of the era in which it was built. Led by Mortenson Construction, the forward-thinking design team comprises architecture firms Bennett Wagner & Grody and HOK, RMH Group (mechanical, electrical, and plumbing engineering), and Rocky Mountain Institute as the high-performance building consultant.