Towering Infernos – Aggravating Factors in Skyscraper Fires
January 14, 2016| By Jon Sigwart
Region: Middle East
The property market in the United Arab Emirates (UAE) has experienced a number of fires at high profile skyscrapers, most recently on New Year’s Eve at the Address Downtown Hotel located near the world’s tallest building, the Burj Khalifa. Whilst the cause and quantum of the loss are currently subject to speculation, we know damage to many skyscrapers has been exacerbated by the exterior wall assembly utilised in construction.
Common exterior wall assemblies include Exterior Insulation and Finish Systems or “EIFS,” a non-structural multi-layered exterior wall system used in both commercial and residential construction. The layer of insulation they contain is usually foamed polymer, such as expanded polystyrene (EPS), though different materials such as non-combustible mineral wool can be used. Its growing popularity is driven by both the energy efficiency and the design flexibility it provides.
There are a number of underwriting considerations when EIFS are present. When a building is well protected with automatic sprinklers and of noncombustible construction, the presence of EIFS cladding will have a minimal effect on internal fire propagation. However, the potential for internal fire spreading via the exterior wall assembly when the property at risk has an inadequate sprinkler system or lacking one completely is much greater. Has sprinkler design and adequacy been considered in conjunction with the EIFS?
Prior to 2012 the UAE Fire & Safety Code had no specific requirements for exterior wall assemblies containing combustible insulation and hundreds of skyscrapers were built throughout the UAE before the code was instituted. Consideration should be given to when the building was constructed and exactly what materials were used.
The finish of the EIFS cladding can also have implications for the exposure presented by adjacent buildings. When exposed to a proximate fire source, the finish of the cladding may not prevent the insulation from catching fire. The insured premises may be a well-managed site with known exposures, but can the same be said for neighboring operations? Does the PML / MFL calculation consider external fire spread?
Property in the Course of Construction can present an additional exposure as there can be a significant amount of loose insulation stored at the site or adhered to the walls and not yet covered. A 2010 high-rise apartment building fire in Shanghai was believed to be caused by workmen carrying out hot works and it was reported the buildings outer wall cladding contained polyurethane (PUR) foam insulation. Are adequate hot work procedures in place? Does the policy include a Waiver of Subrogation that could have an impact on an insurer’s ability to subrogate against liable contractors?
Although fires involving EIFS are rare, the consequences can be severe. Rebuilding work on Dubai’s 34-storey Tamweel Tower still hadn’t started over 12 months after the building was partly destroyed by a fire in 2012.1 Each high-rise building is different and needs to be underwritten based on its individual merits.
At Gen Re we have experience underwriting high-rise structures across the globe, so contact your local property representative if you need support with these exposures.