Buildings currently account for 40% of primary energy consumption in most countries, and are also a significant source of carbon dioxide emissions. The IEA has identified the building sector as one of the most cost-effective sectors for reducing energy consumption. Moreover, by reducing overall energy demand, improving energy efficiency in buildings can significantly reduce carbon dioxide (CO2) emissions from the building sector. To help its member countries achieve their energy security and climate goals, the IEA has come up with policy recommendations based on best practices, such as governments requiring the implementation of building energy codes for both new and existing buildings, and setting overall minimum energy performance standards and mandatory renovation rates to capture the savings potential of the buildings sector. The IEA also develops detailed roadmaps for both the evolution and deployment of efficient technologies.