Commercial building energy policy is a rapidly evolving component of the energy and emission reducing initiatives of major cities. Over 40 cities across the United States have enacted policies with the intention of bringing the commercial building sector into the 21st century as part of the effort to curb energy demand. While some cities have simply adopted benchmarking policies, which require building owners to report their energy usage in comparison to their peers, other cities, like New York, Philadelphia, Boston and Washington D.C., have made their efforts more aggressive with emission limits and strict penalties for non-compliance. This panel will give a broad overview of all methods of energy and emission regulation currently in municipal legislation: benchmarking, auditing, required energy conservation measures, and performance targets. The panel will then discuss the data and results surrounding these policies, and in this way evaluate best practices for the future of efficiency in the built environment of cities. Accomplishing these goals will require actionable data and a public/private partnership involving city governments, utilities, service providers, policy advocates, and private building owners.