The major rehabilitation of the Silvio J. Mollo Federal Building exemplifies building reuse as critical in decarbonizing buildings. By addressing structural, security, and spatial challenges, the project transforms the 1975 concrete structure into a modern workplace that prioritizes daylight and user comfort. Operational carbon is reduced by implementing all-electric systems, allowing the building to be powered by GSA’s renewable electricity purchasing program. While celebrating its heritage, a new façade and entry pavilion reposition the building’s image into a symbol of Justice, reflecting the core values of the U.S. Attorney’s Office.