This document provides general principles for a performance-based methodology for engineers to assess the level of fire safety for new or existing built environments. Fire safety is evaluated through an engineered approach based on the quantification of the behaviour of fire and people and based on knowledge of the consequences of such behaviour on life safety, property and the environment. This document is not intended as a detailed technical design guide, but does contain the key elements needed by practicing fire safety engineers and peer reviewers (those entities who could be required to review the work of fire safety engineers) for addressing the different steps and their linkages in a design process. The information contained in this standard not only is intended to be useful to engineers directly but is also intended to serve as a template to guide the development of a consistent set of fire safety engineering documents covering the role of engineering methods and test methods in performance-based design and assessment. The use of this document as a coordinating guide is illustrated in Annex A where a proposed documents hierarchy consistent with this document is discussed. The basic principles of fire safety design and related fire safety objectives in this document should be applied in any other document addressing phenomena associated with fire (e.g., fire growth, hot gases and effluents movement, structural and compartmentation behaviour). Related fire safety objectives include, for example: • safety of life; • conservation of property; • continuity of business and safety operations; • protection of the environment; • preservation of heritage. Furthermore, these basic principles should be applied to all configurations of the built environment (e.g., buildings, transportation systems and industrial installations). Because prescriptive regulations covering fire safety design will co-exist for some time with performancebased design, this standard takes into account that fire safety designs conforming to prescriptive regulations may become the basis for comparison of engineered designs of new built environments.