More than 50% of the world’s commercial building stock that will be in operation in 2050 is already in use today. The convergence of aging buildings, performance hurdles, and market differentiation will push real estate owners to retrofit their buildings. Many energy conservation measures can deliver paybacks in fewer than five years, but a complex stakeholder web often presents hurdles in financing and aligning differing incentives. In this report, we have identified Energy Service Companies or (ESCOs) as the drivers of the commercial energy efficiency retrofit market and mapped the partnerships of the dominant ESCOs in the U.S., EU, and India. These maps provide insights into the winning strategies in each market – and identify the entry points for other players in the retrofit value chain.