There are over 130 million buildings in the U.S., and owners spend more than $370 billion annually on energy, the U.S. Department of Energy (DOE) reported in 2024. It also reported that buildings use 40 percent of the total energy used in the U.S. In 2022, buildings accounted for over 30 percent of greenhouse gas emissions, according to the U.S. Environmental Protection Agency. Sustainable building technologies may reduce energy use, costs, and emissions. Sustainable building technologies can deliver benefits but may raise construction costs. Savings over a building's life are hard to estimate, and initial owners may not recoup their higher up-front costs. Policymakers and industry have used funding incentives to develop some technologies.