The fire in the Grenfell tower in London has heightened awareness of fire risks in tall buildings in Australia. The pressure to increase height limits and urban density, and to create sustainable and efficient buildings, must not lose sight of the fundamental engineering and design requirements for fire safety, and of the need for robust regulatory oversight of these standards.
The charred and still smouldering Grenfell tower, the as yet unfinished search for the bodies of the victims, and the incandescent rage and grief of the survivors and the public at large are driving governments in the UK and all over the world, including Australia, to urgently commission inquiries into the safety of their tall apartment and office buildings.
It is too early to ascribe blame, but poor initial design and construction, the recent addition of flammable cladding to the building and a failure of ongoing maintenance have all been implicated. Whilst is clear is that this forensic examination must be exacting and the results capable of informing future performance based standards for design and construction of tall buildings, it has brought into sharp focus the vulnerability to fire of modern high rise apartment buildings.
On March 25, 1911 a fire at the Triangle Waist Company factory, which occupied the eighth, ninth, and tenth floors of the 10-story Asch Building in New York was the deadliest industrial disaster in the history of the city, and one of the first fires in a tall building of concrete and steel construction. The fire caused the deaths of 146 garment workers – 123 women and 23 men – who died from the fire, smoke inhalation, or falling or jumping to their deaths.
Most of the victims were young Italian and Jewish immigrant women. Results of the ensuing investigation saw the passage into law of new measures mandating better building access and egress, fireproofing requirements, the availability of fire extinguishers, the installation of alarm systems and automatic sprinklers, better eating and toilet facilities for workers, and limited the number of hours that women and children could work. As a result of the fire, the American Society of Safety Engineers was founded in New York City on October 14, 1911.
The regulatory responses to this and other fires were prescriptive, and constrained the design and performance of each of the elements of a building within strict bounds. Redundancy of these safety factors provided additional insurance against failure.
Ninety years later, in the same city, the forensic investigation into the collapse of both World Trade Towers was the largest in the history of fire safety engineering. What this and other investigations have revealed is that a prescriptive regulatory approach is no longer adequate and that the attainment of fire safety in modern tall buildings is probably beyond the scope of applicability of current fire safety codes and engineering practices.
The innovation and complexity of these buildings, which has enabled their maximum attainable height to exceed 800 metres, needs to be accompanied by performance-based design standards which are based upon rational engineering based strategies for the protection of lives and property. These strategies for tall building safety are essentially a function of time, and have two components – strategies for egress and building performance. The evacuation strategy is concerned with defining the time required to safely evacuate all building occupants. Building performance concerns the time that the structure can withstand the effects of the fire and the compartmentation remain in place and functional. The design guidance for tall buildings emerging from the World Trade Center investigation has begun to address these issues but there still seems to be a reluctance to accept that traditional fire safety methods such as furnace derived fire resistance and sprinklers as the primary strategy, cannot provide the requisite levels of safety.
After Grenfell, the most urgent issue in Australia is an assessment of risks of existing aluminium composite panelling, which has been widely used in Australia over 25 years. In response to a fire in the Lacrosse building in Melbourne in 2014, the Victorian Building Authority conducted an audit of external cladding used on 170 high rise residential and public buildings in Melbourne that were constructed in the past 10 years. They found a non-compliance rate with existing standards of 51% and two buildings were deemed to require immediate remedial action. After considerable delays the Australian Building Codes Board issued a National Advisory in 2016 and canvassed a number of regulatory options to limit the uptake of these products.
Since the Grenfell fire there have been calls for a Senate Inquiry into the risks of a similar catastrophe here in Australia. It may be timely for such an inquiry to broaden its scope. The latest crane count in our capital cities is over 650, close to its peak of 666 in September 2016. Eighty four percent of these are residential towers and one half are in Sydney. The pressure to increase height limits and urban density, and to create sustainable and efficient buildings, must not lose sight of the fundamental engineering and design requirements for fire safety, and of the need for robust regulatory oversight of these standards.
Stephen Corbett is a public and environmental health physician and is currently Director of the Centre for Population Health in Western Sydney Local Health District. He is an Associate Professor in the School of Population Health and the Western Clinical School at the University of Sydney and an Associate Editor of Evolution, Medicine and Public Health.