Overview
ISO/TR 24188:2025 - Large outdoor fires and the built environment - Global overview of different approaches to standardization is a Technical Report from ISO/TC 92 that reviews global testing methodologies and land use management practices related to the vulnerabilities of buildings to large outdoor fires. The report surveys ignition scenarios (wildland‑urban interface/WUI fires, post‑earthquake fires, tsunami‑ or volcano‑generated fires, and informal settlement fires), summarizes how different jurisdictions regulate ignition risk, and catalogs test approaches for building elements exposed to external fire hazards.
Key topics and technical scope
- Ignition scenarios: three primary mechanisms are described - direct flame contact, thermal radiation, and firebrands - including combinations and implications for spotting and fire spread.
- Regulation principles and strategies: comparative overview of national/regional approaches (examples include Japan, California building code, NFPA 1144, IWUIC, France, Australia).
- Standard test approaches: overview and classification of tests relevant to external exposures, including methods for roofing assemblies, exterior walls and facades, and other elements (vents, decks, eaves, windows).
- Reaction‑to‑fire provisions: noted jurisdictional differences (e.g., California, France) in how reaction‑to‑fire testing is applied to reduce structure ignition hazards.
- Land use management practices: how zoning, buffer zones and urban planning interact with building‑level measures to mitigate large outdoor fire risk.
- Informative annexes: examples such as the European CEN/TS 1187 roof test description are provided for reference.
Practical applications
ISO/TR 24188:2025 is a guidance and review document useful for:
- Building code and standards developers seeking cross‑jurisdictional perspectives on external fire testing and regulation.
- Fire safety engineers and researchers evaluating building vulnerability, designing mitigation measures, or developing test methods for large outdoor fires.
- Architects and manufacturers of roofing, cladding and facade systems requiring awareness of external exposure risks and relevant test approaches.
- Urban and land‑use planners integrating zoning, defensible space and fuel management to reduce WUI and large outdoor fire impacts.
- Insurance and risk assessment professionals estimating exposure and losses from external fire scenarios.
Related standards and references
The report cross‑references national codes and existing standards such as NFPA 1144, International Wildland Urban Interface Code (IWUIC), CEN/TS 1187, and ISO/TS documents (e.g., ISO/TS 19677) as context for global standardization approaches.
ISO/TR 24188:2025 is a practical resource for harmonizing test practices and informing policy decisions to reduce the impact of large outdoor fires on the built environment.