Overview
ISO/TS 29761:2015 - Fire safety engineering - Selection of design occupant behavioural scenarios - provides a structured methodology for selecting severe but credible occupant behavioural scenarios for deterministic fire safety engineering analyses. The Technical Specification focuses on life safety of occupants in any built environment (buildings, structures, transportation vehicles) and links occupant behaviour scenarios directly to design fire scenarios. It addresses occupant actions and movement after fire ignition (it does not cover behaviours that influence ignition).
Key topics and requirements
- Purpose: select a manageably small set of design occupant behavioural scenarios that are appropriate for deterministic analyses of egress and life safety.
- Scope: applies to any built environment including buildings, tunnels, ships, offshore platforms, and vehicles.
- Core elements:
- Identification of occupant distribution and population characteristics (number, age, mobility, training).
- Definition of design occupant behaviour (pre-travel activity times, travel speeds, exit choice).
- Consideration of systems and features that impact fire and egress (detection, suppression, signage).
- Steps mapped to ISO 16733‑1 for selecting design fire scenarios, with life safety as the single objective.
- Use of ASET (Available Safe Escape Time) as a key concept to evaluate incapacitation and escape potential.
- Guidance on scenario selection, documentation and sensitivity analysis of parameters affecting life-safety metrics.
- Methods for estimating evacuation time using simple and advanced calculation techniques; reference to tests and further quantification methods in ISO/TR 16738.
- Constraints: intended for deterministic assessment; full quantitative risk assessments are directed to ISO 16732‑1.
Practical applications
- Use ISO/TS 29761:2015 to produce defensible, conservative occupant behaviour inputs for:
- Fire safety engineering reports and performance-based design.
- Egress and evacuation modelling for buildings, transportation vehicles, tunnels and other structures.
- Design reviews where life safety and ASET calculations guide fire protection measures.
- Benefits:
- Ensures consistent, traceable selection of occupant scenarios for analyses.
- Helps focus modelling effort on the most critical occupant behaviours that influence evacuation outcomes.
- Supports design decisions on detection, alarm strategies, staffing and signage to achieve life‑safety objectives.
Who should use it
- Fire safety engineers and consultants
- Building designers and architects involved in performance-based design
- Evacuation modelers and researchers
- Regulators, building control authorities and transport safety assessors
- Emergency planners and facility managers
Related standards
- ISO 16733‑1 - Selection of design fire scenarios and design fires (linked methodology)
- ISO/TR 16738 - Methods for evaluating behaviour and movement of people (quantification guidance)
- ISO 13571 - Estimation of time to compromised tenability (ASET-related guidance)
- ISO 13943 - Fire safety vocabulary
Keywords: ISO/TS 29761:2015, fire safety engineering, design occupant behavioural scenarios, occupant behaviour, evacuation modelling, ASET, design fire scenarios, deterministic analysis, egress design.