- Active. The design of structural fire resistance requires three major steps: (1) determination of the thermal exposure to a structure resulting from a fire (2) determination of the temperature history within the structure, or portion thereof, and (3) determination of the structural response. This standard is limited to the second step in this process. The standard provides requirements for the development and use of methods to predict the thermal response of structures using listed fire resistive assemblies to time dependent thermal boundary conditions imposed by fires. It provides requirements for calculation methods that provide time dependent temperature field information resulting from fire exposures required for engineered structural fire design (including structural systems and fire barriers). The Annex provides precisely calculated reference temperatures from 16 verification cases that represent a variety of problems that are relevant in fire safety engineering