Even though the world’s first skyscraper, built 133 years ago, was designed to safeguard against disasters like the Great Chicago Fire of 1871, high-rise buildings across the globe are still hardly safe from blazes. According to the National Fire Protection Association (NFPA), enforcement authorities and those responsible for managing large portfolios of high-rise buildings have lacked a tool to assess and prioritize remediation works. After seven months of work and testing, on February 5, the NFPA has launched a new tool called the “Exterior Facade Fire Evaluation Comparison Tool” (EFFECT™), to help building owners, facility managers and authorities having jurisdiction (AHJs) proactively assess risk in their high-rise building inventory with combustible facades. It was tested in several phases by Arup, the developers of the methodology commissioned by the NFPA, and a group of BETA testers consisting of authorities from the U.S., Canada, and the U.K.
We speak to the NFPA’s Director of Applied Research, Birgitte Messerschmidt, about how the EFFECT™ tool can be used by building owners, facility managers, and AHJs to assess hazards, prioritize inspections, and remediate issues. “When it comes to big fires, there’s often more than one factor, so you have to look at fire and life safety more holistically – not just the exterior panels,” she says.
A good example of the importance of assessing fire risk is an incident that happened last year in the British capital. Before the sun rose one morning in June 2017, a fire broke out in London’s 24-story Grenfell Tower. By mid-day, the death toll had reached 79, with dozens missing and presumed dead. “In my 29 years of being a firefighter, I have never, ever seen anything of this scale,” said Dany Cotton, the commissioner of the London Fire Brigade. Two weeks after the tragedy, London police confirmed that the fire was started by a fridge, which raised questions about how a fire that began in the kitchen of one apartment spread so rapidly though a 24-story high-rise building with 120 apartments. Such incidents shake the confidence that security engineers have in high-rise buildings. In spite of that, they still defend their case, saying that skyscrapers utilize very conservative construction materials, also known as fire-resistive construction.
Messerschmidt tells progrss that EFFECT™ is a global tool that can be used anywhere. “The urgency in the U.S. is no different than other countries with high-rise buildings,” she elaborates.
How Does EFFECT™ Work?
The tool asks the building owners, facility managers, and AHJs a list of specific questions about the building, the materials used in the façade, and potential ignition sources. Messerschmidt tells us that some examples include: Is the insulation provided within the building façade made of a combustible material, e.g. foam insulation? Are the outer cladding panels of the façade system of the building made of a combustible material? Is a sprinkler system provided throughout the building? Are there combustibles against the façade such as parked cars or trash? Is a fire alarm and detection system provided within the building? Are there two or more staircases available for evacuations?
“The answers provide the information the tool needs to determine if there is a risk of ignition and fire spreading up the façade and if the alarm systems and escape routes are appropriate for the type of building,” she explains. The tool then produces the results showing the risk score for each major area; insulation, cladding, ignition risk, alarm system, escape routes, etc. Based on the score, the user can run the assessment again with different options to see what changes could reduce the risk.
EFFECT™ is a desktop tool that takes an all-factors approach and employs a two-tiered risk-assessment process. Users can obtain it by going to the exterior walls page on NFPA’s website where there is a link to the tool as well as information needed to register.
In the second tier, authorities conduct a deeper fire risk assessment evaluation that requires them to obtain information related to onsite inspection, including built information, maintenance records, and samplings and laboratory testing of unknown facade materials.
“Assessing risk is not easy work, but it is necessary,” Messerschmidt says. “EFFECT™ can have a significant impact on high-rise building safety as it makes it possible for authorities and building owners to assess the risk of their existing buildings and identify mitigation efforts if needed.” The tool is aimed at property managers and enforcers who might not have the time to go and evaluate their buildings the old-school way.
As high-rise fire incidents increase and the push for densifying cities continues, urban security engineers are increasingly trying to find a solution out of this problem. In June 2017, a group of engineers conducted a study in which they proposed a special spiral slideway for better, faster, and more efficient evacuations in skyscrapers. The solution – as the name suggests – involved installing a spiral slideway device equipped with a shunt valve as a standard feature of skyscrapers. The slideway would enable people escaping fires to slide down to the first floor using gravity, without the aid of electrical power, making it suitable for emergency evacuations and inclusive of mobility-impaired people.
The slideway is designed with alternating clockwise and counterclockwise spirals so as to ensure that those who ride it will not become dizzy as they descend. The researchers recommend that people evacuating using the slideway wear some sort of protection padding, since friction with the slide could cause injuries.
According to their calculations, the engineers found that people in emergency situations could potentially evacuate buildings faster using the slideway than they would using traditional staircases. Aside from functioning as a fire exit, the slideway could also be used as an alternative to stairs and elevators in skyscrapers, potentially saving time and energy in day-to-day use.
“Until it has been tested on a larger scale it is difficult to predict if it will actually work,” Messeschmidt comments, when asked about her opinion on the “special spiral slideway.” She stresses that the human behavior aspect is an important part of evacuation process, which has not been sufficiently considered yet for the slideway-method.