ISO 16733-1:2024

Overview

ISO 16733-1:2024 - "Fire safety engineering - Selection of design fire scenarios and design fires - Part 1: Selection of design fire scenarios" - specifies a methodology for selecting a manageable set of design fire scenarios for fire‑safety engineering analyses of any built environment (buildings, structures, transportation systems). The standard defines how to reduce the large universe of possible fire events to a focused set suitable for qualitative or semi‑quantitative analysis. It complements quantitative risk‑based approaches (see ISO 16732-1) and aligns with the performance‑based fire safety process in ISO 23932-1.

Key topics and technical requirements

• Objective-driven scenario selection: Scenario choice is tied to fire‑safety objectives such as life safety, property protection, environment and heritage conservation.
• Definitions and scope: Clear terms for design fire, design fire scenario, fire scenario cluster, and representative fire scenario.
• Stepwise methodology: A structured nine‑step process for identifying and selecting design fire scenarios, including:
  • Step 1 - Specific safety challenges
  • Step 2 - Location of fire
  • Step 3 - Type of fire
  • Step 4 - Complicating hazards
  • Step 5 - Systems and features impacting fire
  • Step 6 - Occupant actions
  • Step 7 - Formulating scenario clusters and selecting representative scenarios; guidance on completeness and exclusions
  • Step 8 - Consideration of system availability and reliability
  • Step 9 - Final selection and documentation
• Scenario clustering and representation: Grouping similar scenarios into clusters and selecting representative scenarios for analysis to manage workload while maintaining fidelity.
• Documentation and justification: Requirement to document selection rationale, assumptions and completeness checks.
• Informative annexes: Annex A provides data considerations for scenario development; Annex B gives example explicit fire scenarios.
• Normative references: ISO 13943 (vocabulary), ISO 16730-1, ISO 16732-1, ISO 23932-1.

Practical applications and users

ISO 16733-1 is aimed at professionals engaged in performance‑based fire safety and fire risk assessment:

• Fire‑safety engineers and consultants selecting scenarios for deterministic or semi‑quantitative analyses.
• Design teams and architects integrating fire safety into building and transport infrastructure projects.
• Regulatory authorities and code officials reviewing engineered fire safety submissions.
• Risk assessors and facility managers tailoring protection measures to credible worst‑case scenarios.

Typical applications include evacuation modelling, smoke control design, structural fire engineering, fire suppression system design, and performance verification of fire protection strategies.

Related standards

• ISO 16732-1 (fire risk assessment, quantitative approach)
• ISO 23932-1 (performance‑based fire safety process)
• ISO 13943 (fire safety vocabulary)
• ISO 16730-1 (verification and validation of calculation methods)

Keywords: ISO 16733-1, design fire scenarios, fire safety engineering, selection of design fire scenarios, design fire, performance‑based fire safety, fire risk assessment.