Many state policymakers and utility regulators have established aggressive energy efficiency (EE) savings targets which will necessitate investing billions of dollars in existing buildings. Tax payer and utility bill payer funding is a small fraction of the total investment needed. Given this challenge, some EE program administrators are exploring ways to increase their reliance on financing with the aim of amplifying the impact of limited program monies. This book explores the rationales and design options for energy efficiency financing programs; discusses increasing Middle America's access to capital for energy improvements; and provides insight on the limits of financing for energy efficiency.