Many federal agencies have developed and embraced principles of sustainable design. These principles strike a balance between the need to fulfill an agency's mission in cost-effective buildings and the need to protect workers, the environment, and other resources. Agencies have the leverage to convert these principles into effective design practices through the procurement of architectural and engineering (A/E) services for energy-efficient, sustainable new construction. The two most important elements in the procurement process are the selection criteria and the statement of work. The section on establishing selection criteria contains key elements to consider before you actually select an A/E firm. The section on preparing the statement of work discusses the broad spectrum of sustainable design services that an A/E firm can provide for your federal project.