20.500.12556/DiRROS-24440 Principles for the fire performance of external wall systems Recent high-profile fires involving combustible façades have exposed significant gaps in both the understanding and regulation of external wall systems. Modern façade designs frequently employ polymers as insulation and/or laminated composite materials that, while improving energy efficiency, can inadvertently create pathways for vertical fire spread. Thus, there is a need to establish fundamental principles for evaluating the fire spread performance of these systems. Drawing on notable incidents, it is shown how uncontrolled flame spread can defeat compartmentation strategies, compromise occupant egress, and overwhelm firefighting efforts. Extending on previous studies, a performance-based approach to fire spread is proposed, examining four levels of relevance: material properties, product characteristics, assembly configuration, and overall building context. Key factors include combustibility, ventilation effects, and real-world variables (e.g., building characteristics). Case studies of testing methods illustrate both utility and limitations in capturing metrics relevant to façade design. Ultimately, it is advocated that there is an urgent need for rigorous, tailored assessment protocols supported by professional competence, thereby ensuring that complex external wall systems can be designed and managed to balance fire safety with sustainability and safety objectives. fire safety facades external wall systems fire spread požarna varnost fasada zunanji stenski sisitemi širjenje požara toplotni tok true false true Institute of Physics Publishing Angleški jezik Slovenski jezik © authors, 2025 Neznano 2025-11-28 09:48:36 2025-11-28 10:02:37 2025-11-29 03:56:25 0000-00-00 00:00:00 2025 0 0 Str. 1-6 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2025-09-01 62 1742-6596 10.1088/1742-6596/3121/1/012020 256631043 253630979 https://doi.org/10.1088/1742-6596/3121/1/012020 0 0b8d0b46-cc37-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=36396 RAZ_Lucherini_Andrea_2025.pdf RAZ_Lucherini_Andrea_2025.pdf 1 B16D33745D130E9541B2BD3678E03AAA 5270504a9fc86fa170498417b8128001da75eb1d94553bd615c32eb7121bfc0b f71a2511-cc38-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=36400 Zavod za gradbeništvo Slovenije 0 0 0