As a significant source of emissions, cities have an important role to play in addressing the carbon footprint of activities occurring within their boundaries. Among many actions targeting different sectors, cities are actively pursuing improvements in the energy performance of commercial buildings. This brief explores several policies that leading cities are adopting: energy use benchmarking and disclosure mandates, retro-commissioning and retrofitting policies, and requirements for building upgrades to meet current codes. Our review finds these policies stand to deliver and facilitate emissions reductions in cities that adopt them. However, it should be noted that achieving deep reductions and a true market transformation will require collaboration between cities, state and federal agencies, and a range of non-government entities. The need for such a collaborative approach is applicable not just to addressing emissions from buildings, but indeed is relevant broadly to city efforts to reduce emissions.