For Chinese student Ginger Jiang, recounting the night her life changed because of fire in the Sydney suburb of Bankstown in September 2012 was gut-wrenching.
“The smoke was too strong. We couldn’t breathe,” Jiang told a coronial inquest into the fire in 2015.
Along with friend and fellow student Connie Zhang, Jiang had become trapped on a ledge outside a bedroom as fire which started on a balcony tore through a fifth floor apartment.
Both Jiang and Zhang jumped. Jiang is now confined to a wheelchair. Zhang did not make it.
Jiang said the fire was so ferocious that the metal frame of the bedroom window was melting in her hand.
“I thought if I don’t jump, I’ll die in here. So I jumped,” she recalled.
Amongst other findings, the Coroner’s report into that incident concluded that despite being centimetres less than 25 metres in effective height, the building should have had sprinkler protection due to the presence of an atrium. Had such a system been installed, it was likely that both Zhang and Jiang would have not only both survived but also escaped serious injury.
As things stand, sprinklers are not mandatory under the National Construction Code (NCC) in multi-storey residential buildings in cases where the effective height of the building is less than 25 metres. In such cases, the safety of residents in the event of a fire rests largely upon early detection through alarm systems, ‘passive fire protection’ through fire resistant walls, floors and doors among other things to contain the fire to the point of origin and prevent or slow its spread. Any suppression of the fire occurs only via fire extinguishers, should the occupants choose to use them, or fire hydrants supplying water to responding fire crews.
That, however, may be about to change. Following one of the Coroner’s recommendations, Fire & Rescue NSW worked with Fire Protection Association Australia (FPA Australia), the CSIRO and the Australasian Fire and Emergency Service Authorities Council (AFAC) on a multi-year program to undertake testing in order to support a Proposal for Change to mandate fire sprinkler systems in the 2019 National Construction Code for new Class 2 and Class 3 shared residential accommodation buildings of up to 25 metres in effective height.
As part of this, FRNSW and its partners developed two sprinkler concepts for Class 2 and Class 3 buildings. One involves tapping water from the hydrant system, while the other taps into water from the domestic water supply.
As part of the program, systems using these concepts and varying configurations were subject to 14 ‘live’ burn events inside a purpose-built facility based on the Bankstown apartment floor plan.
Critically, the systems were designed to be not only reliable but also cost effective. This is important as prohibitive costs are the predominant reason that sprinklers are not routinely installed now in residential complexes below 25 metres.
The results were striking:
- At no point in any of the tests involving sprinklered apartments did the temperature reach the point of ‘flashover’ – the point typically reached where temperatures can reach over 1,000 degrees Celsius and all combustible material in the room has ignited and the fire is non-survivable. In fact, the highest temperature reached in any of the sprinklered tests was 372 degrees Celsius (and flashover was thus not reached). By comparison, in the non-sprinklered burn of the test apartment, flashover was reached at 3 minutes 42 seconds.
- Toxicity levels in sprinklered tests did not exceed limits set for the tests (Fractional Effective Dose 0.3) until an earliest mark of 14 minutes and 42 seconds. This compares with 3 minutes and 50 seconds in the case of the non-sprinklered test.
- In none of the sprinklered tests bar one was a third tenability criteria involving a temperature exceeding 65 degrees Celsius at 1.6 metres in height above the ignition point exceeded to a significant degree.
- In all cases involving sprinklered tests, the fire was contained to the area of origin. In all sprinklered tests, the fire did not spread beyond the room of origin.
As a result of these findings, a Proposal for Change has been submitted to the Australian Building Codes Board to amend the current requirements. This has been supported to be included in the NCC Public Comment Draft for 2019. Under this proposal, sprinklers will be mandated in all new Class 2 and 3 buildings, as well as Class 4 parts of a building that are greater than three storeys in height but less than 25 metres in effective height (existing requirements for sprinklers in buildings of greater than 25 metres will remain). The system installed will have to comply with either the current sprinkler standards or with new sprinkler specifications written by the FPA Australia, informed by the testing.
In light of the additional protection delivered by the sprinklers, however, builders and developers may be afforded concessions in respect of other requirements, depending on the system used. These relate to areas such as passive fire protection and maximum travel distances.
NSW Fire & Rescue assistant commissioner Mark Whybro said the importance of sprinklers should not be underestimated. While the early detection associated with smoke alarms increases the likelihood of surviving residential fires by 50 per cent, he says this rises to more than 80 per cent when sprinklers are added. This is critical as residential fires account for only 16 per cent of Fire & Rescue NSW callouts, but over 90 per cent of fire-related fatalities.
While passive fire protection works to contain fire within the ‘box’, it is sprinklers that control and suppress the fire to afford those trapped inside time to escape, Whybro said. Furthermore, he says sprinklers deliver a more favourable environment when fire crews arrive.
He describes the phenomenon of sprinklers not being mandatory in apartment complexes of less than 25 metres in effective height as an ‘anomaly.’
“Not only does it (having sprinklers) improve tenability for occupants by controlling and suppressing the fire, reducing temperatures and giving them more time to escape, it’s also a much better operating environment for when fire crews arrive and have to intervene,” he said.
“The key to this is not only the occupant’s safety – which is primary because they are on scene in the fire – it’s also the firefighters who have to then come in and extinguish the fire.
“The sprinkler system goes off and it supresses the fire. Ten or fifteen minutes later when crews come through the door, temperatures are lower.”
Matthew Wright, deputy chief executive officer of FPA Australia, says the need for sprinklers is being driven by decreases in flashover times. As recently as 50 or 60 years ago, flashover times stood at 20 or 30 minutes. This afforded occupants time to escape without the need for sprinklers. Courtesy of the growing prevalence of synthetic material within modern apartments (such as furniture and consumer goods), however, flashover times in non-sprinklered apartments now stand at around three and a half minutes. This is well short of the seven, eight or nine minutes it takes fire crews to arrive at the curb.
In this environment, Wright says reliance upon early detection systems, passive fire protection and hydrants alone is no longer adequate.
“The speed of fire growth in modern residential buildings has been shown to be eight times faster than it was 50 years ago. This means that there isn’t enough time for the fire brigade to respond and put water on the fire in time to make sure that people continue to be safe,” he said.
“The value of sprinklers is that they operate independently of the fire brigade. And they have been shown by this research to either extinguish or control fire growth and give you enough time to make it out alive.”
Moreover, Wright said the systems tested have been shown to be cost effective. Tapping into the existing pipes which supply hydrants now avoids the need for separate pipes to be installed simply for the sprinklers. Tapping into the domestic water supply also uses existing infrastructure, but has additional benefits. First, with the head of the sprinkler system not being dissimilar to a tap fitting, installing this type of arrangement becomes a simple exercise of placing the system in the correct location.
Moreover, under this approach, any issues associated with the sprinkler water supply (connected to the domestic water supply) will be identified as soon as problems are detected with the domestic water supply (when residents attempt to use water). This avoids the situation whereby sprinklers could be inadvertently turned off without anyone realising until it was too late.
As well as efficient design, cost effectiveness will also be facilitated by the aforementioned concessions to other requirements which the additional protection delivered by the sprinklers has afforded. Maximum travel distances can be increased as people can be afforded more time to leave because the sprinklers are controlling the fire. This may afford developers the opportunity to get more apartments into the complex and thus generate greater return on investment. Rationalised requirements for passive fire protection, meanwhile, will help to minimise cost further.
Indeed, Wright says that in some instances where the FPA Australia sprinkler specification(s) are used for Code compliance, the system will in fact be cost neutral compared with current requirements where there are no sprinklers.
This is important, he says, as cost is holding back adoption of sprinklers in low-rise apartments now.
“We could have put sprinklers in under the current standards, but the cost of that would be a significant roadblock in an industry that works on tight profit margins,” Wright said.
“We have tried to come up with a design that reduces the cost of the sprinkler installation itself. Also, because we have sprinklers and we know that they are reliable as demonstrated by testing and historical data, it gives you some other concessions in relation to compliance with the Code, which improve the (developer) margins.”
For years, concerns about a lack of sprinklers in residential buildings below 25 metres have been raised.
Now, they have been shown to be reliable and cost effective. Their mandatory adoption, it seems, is likely to happen in NCC 2019.