The document outlines the substantial opportunity presented by building energy efficiency retrofits in the U.S., with an estimated investment potential of $279 billion that could lead to over $1 trillion in energy savings and 3.3 million job years created. It discusses various financing models such as energy service agreements and property assessed clean energy to overcome barriers to adoption and scale investment in retrofits. The report emphasizes the climate benefits, including a potential reduction of nearly 10% in U.S. emissions, highlighting the significance of energy-efficient upgrades in addressing both economic and environmental challenges.