This best practices document is prepared as part of the response to the recommendations from the October 2003 NIST-SFPE Workshop for Development of a National R&D Roadmap for Structural Fire Safety Design and Retrofit of Structures. The workshop was jointly organized by the Society of Fire Protections Engineers (SFPE) and the National Institute of Standards and Technology (NIST) with guidance from an industry steering team comprising of representatives of the American Institute of Steel Construction (AISC), the American Society of Civil Engineers (ASCE), Portland Cement Association (PCA), Underwriters Laboratories (UL), Arup Fire, and National Fire Protection Association (NFPA). The document aims to integrate information on current "best practices" in fire resistance engineering in the United States and overseas with current best knowledge in fire risk assessment and characterization, material properties and responses at high temperatures, and thermal and structural response calculation methods into a single source document, and to provide engineers and code enforcement officials with a technical resource for use in their approach to fire resistance design and evaluation of concrete and steel structures.