The Concepts of Safety Level and Safety Margin: Framework for Fire Safety Design of Novel Buildings

This article discusses how the concepts of safety level and safety margin have been approached in recognized peer-reviewed journals within the field of fire safety science. The aim is to explore the scientific efforts that have been made to advocate principles for dimensioning fire safety arrangements in buildings. We restrict our discussion to novel buildings in the sense of lack of similar constructions with relevant long term experience. Due to increasing complexity in buildings, infrastructures, technical systems and society in general, we argue that traditional fire safety science based on natural science principles alone is severely limited. We argue that fire safety and safety margins are emergent properties of socio-technical systems that need to be managed rather than verified. The search for objectivity and mechanistic decision criteria is futile and diverts attention from the main purpose of engineering: to guide decisions during the whole design process and thus enable safe operation. An adapted framework for fire safety engineering is proposed, built around traditional fire safety engineering principles, and founded on constructivist systems theory. The focus is observable quantities and how these quantities can be managed during design and operation of a building project. The framework eases the involvement of stakeholders who are required to consider the safety aspects of the building design. The end goal of fire safety design in our framework is the development of a fire safety control structure that must be enforced to keep systems in a safe state, in which safety margins are deemed sufficient.