Combustible Panels

Throughout the United States and internationally, thousands of buildings continue to contain combustible exterior wall systems, including aluminum composite material (ACM) panels with polyethylene cores. Since the 2017 Grenfell Tower fire in London that took more than 70 lives, combustible cladding has become one of the most significant building safety issues globally. Governments, insurers, and regulators have undertaken extensive remediation programs, revised building codes, and increased scrutiny of high-rise buildings containing combustible exterior wall systems. The issue has evolved from a fire protection concern into a broader governance, financing, and insurance challenge.

Background

Combustible cladding is a siding, panel or application that is composed of all or in part of combustible materials used on the exterior side for aesthetics and to resist rain, sleet, snow and wind loads. It contains a polyethylene core covered by thin sheets of aluminum and derived from petroleum or natural gas. The panels can be easily bent and curved to add design versatility and create architectural aesthetics that are challenging to achieve with traditional construction materials. They first entered the U.S. from Europe following the 1970s energy crisis to optimize preservation, improve energy efficiency, and cut costs. However, despite the benefits, the panels are highly flammable and lead to rapid combustion during a fire. Compounded with lenient building codes and regulatory loopholes, thousands of buildings were covered in combustible panels at their peak market use.

Today, many buildings exceed the height of standard firefighter ladders, which typically extend to 40 feet. Tall buildings covered in a combustible exterior can significantly accelerate fire spread, allowing flames to move rapidly up a building’s façade and bypass compartmentalized fire protection measures. This can lengthen evacuation time for residents and create challenges for firefighters. The risks associated with combustible cladding have been well documented, prompting manufacturers, regulators, insurers, and building owners to reexamine the use of these materials in both existing and future construction projects.

The dangers of combustible cladding are not limited to a single jurisdiction or building type. The 2017 Grenfell Tower fire in London brought international attention to the issue, but similar polyethylene-core aluminum composite panels have been identified on a wide range of structures across the United States, including schools, hotels, sports venues, airports, and high-rise residential buildings. While many jurisdictions have strengthened building safety requirements in recent years, the widespread use of combustible cladding makes it difficult to determine exactly where these materials remain in use.

Injuries and Damages

Combustible panels have been linked to tragic disasters around the globe.

Grenfell Tower Fire

In the early hours of June 14, 2017, a fire broke out in a fourth-floor kitchen at Grenfell Tower, a 24-story residential building in North Kensington, London. The fire quickly spread from the apartment to the building’s exterior, where combustible cladding and insulation allowed flames to travel rapidly up the façade. More than 200 firefighters and 40 fire engines responded, but the scale and speed of the fire overwhelmed firefighting efforts. The fire burned for more than 24 hours, over 250 residents were evacuated, and it took 72 lives.

Grenfell Tower had recently undergone renovations addressing both the exterior cladding and insulation. Although zinc cladding was originally proposed, it was replaced with a less expensive and highly flammable aluminum composite material system. Both the cladding and insulation on the outside of the building failed all preliminary tests by police. The exterior wall included polyethylene-core aluminum composite panels, combustible insulation, and a cavity behind the cladding that helped channel flames upward. The building also lacked interior sprinklers, which further limited available fire protection and evacuation time.

The Grenfell Tower Inquiry’s Phase 2 Report, published on September 4, 2024, concluded that the disaster was the result of systemic failures across the construction, manufacturing, regulatory, and government sectors. The report criticized the conduct of product manufacturers, contractors, consultants, local authorities, and regulators to determine that unsafe materials were marketed and approved through fragmented building safety codes.

Following Grenfell, the British government found that over 75 buildings failed standard combustibility tests. What began as a focused review on unsafe ACM cladding systems expanded into a national building safety program covering both high-rise and medium-rise residential buildings addressing critical fire safety defects. The Department for Communities and Local Government assuredly stated that composite aluminum panels with a polyethylene core should not be used as cladding on buildings exceeding a height of 18 meters. Since the fire, more than 259 of 600 buildings across the country have failed fire-safety tests. The government’s remediation portfolio now includes the ACM Programme, Building Safety Fund, Cladding Safety Scheme, developer remediation contracts, and social housing remediation efforts.

Criminal investigations remain ongoing. In May 2026, the Metropolitan Police stated that it expected to submit all charging files to the Crown Prosecution Service by the end of September 2026. Potential charges under consideration include corporate gross negligence manslaughter, gross negligence manslaughter, fraud, health and safety offenses, and misconduct in public office.

Fire in Azerbaijan

In May 2015, an apartment building in the city of Baku, Azerbaijan, killed 15 people and injured more than 50 others who remained trapped in the 16-story apartment building as it was engulfed in flames. Polyethylene-core panels were found to be the main component in the building’s exterior. As a result, six people, including the general director for the local company that made the panels, were tried and convicted of safety violations and sentenced to prison for their role in the deaths of 15 of the building’s residents.

In the U.S.

The United States is also facing its fair share of problems with combustible, polyethylene-core panels. The lack of a centralized regulating and logging authority has made it nearly impossible to identify every building where these panels have and are being used, with some regions having more problems than others. For example, New York City, the skyscraper capital of the world, doesn’t allow combustible-core panels on buildings above 50 feet and has shown no sign of adopting a more relaxed standard. The city remains steadfast that combustible-core panels are not intended for high-rise, curtain-wall construction, even if the building is equipped with an interior sprinkler system.
In September 2007, in the midst of construction of the 43-story Borgata Water Club Hotel in Atlantic City, New Jersey, a near-tragedy struck. A fire broke out on the third floor and flames roared up the building’s exterior with such force that they sent the exterior panels flying over 2000 feet. Had the building been occupied, mass casualties would have been inevitable. The fire occurred in a modern building using combustible panels under modern building codes. At the time, New Jersey abided by a code that restricted combustible metal panels to 50 feet above the ground. As a result, the owner of the hotel sued more than 18 different contractors over a fire that should have never occurred in the first place.
Some contractors argue that the panels do not present a problem for buildings equipped with functional sprinkler systems. But fire safety experts caution that indoor sprinklers cannot stop a fire that ignites on a building’s exterior and spreads across the coating that encases it. The whole outside of a building could be on fire and the internal sprinklers won’t ever activate.

Dubai Skyline

The United Arab Emirates also experienced a slew of fires across the famous Dubai Skyline. These fires were associated with the construction of buildings using combustible panels. Since 2012, six high rises using combustible panels have caught fire. This included the famous Torch Tower, which burned twice in two years. Dubai has since amended its building code to require fire-resistant panels and began in September 2015 to work with owners to replace the exterior of buildings constructed with combustible panels.

Legislation and Regulation

United States Regulatory Framework

The U.S. regulates construction through various codes that are adopted and enforced by state and local jurisdictions. As a result, governance over combustible cladding and exterior walls varies across jurisdictions, although most states rely upon versions of the International Building Code (IBC) as the foundation for their building regulations.

The International Building Code, developed by the International Code Council (ICC), establishes minimum requirements for the design, construction, and maintenance of buildings. Historically, the IBC has imposed stricter fire performance requirements on exterior walls in buildings exceeding 40 feet due to the safety risks of high-rise structures and limited firefighting capabilities at those heights. While local jurisdictions retain authority to adopt and amend building codes, the IBC has become the predominant regulatory standard throughout the United States.

The Evolution of Exterior Wall Fire Testing Requirements

The regulation of combustible cladding in the U.S. has evolved over the past two decades. Initially, ICC provisions restricted combustible panels on high-rise buildings unless those systems successfully demonstrated compliance with prescribed fire testing requirements.

However, in 2009, the ICC modified portions of its exterior wall provisions to permit certain combustible materials under specified conditions. This reflected a growing emphasis on performance-based design and the evaluation of complete wall assemblies rather than individual products in isolation. Conditions included the requirement for an interior sprinkler system, at least 20-feet of clearance from other buildings, and panels that would not cover more than half of a building exterior.

The revisions generated substantial debate within the fire protection community. Following the Grenfell Tower fire and other façade-related fires worldwide, regulators, insurers, and code officials renewed scrutiny of combustible exterior wall systems and the assumptions underlying earlier code changes.

Today, compliance discussions concerning combustible cladding are largely centered on National Fire Protection Association (NFPA) 285, Standard Fire Test Method for Evaluation of Fire Propagation Characteristics of Exterior Wall Assemblies Containing Combustible Components.

NFPA 285 evaluates the fire performance of the entire exterior wall including cladding, insulation, air barriers, framing components, and attachment systems. The test is intended to assess the potential for vertical and lateral flame propagation when a fire originates within a building and extends through a window opening to the exterior façade. As modern façade systems have become increasingly complex, regulators and fire protection professionals have recognized that individual material ratings may not accurately predict how a complete wall assembly will perform during an actual fire event. This makes NFPA 285 one of the principal benchmarks for evaluating combustible components in exterior wall construction in the U.S.

Despite significant improvements in building safety oversight since 2017, several regulatory challenges remain. The ICC does not maintain an inventory of buildings containing combustible cladding systems. As a result, determining the extent of existing exposure remains difficult, particularly for older buildings constructed under previous code editions.

United Kingdom

The Grenfell Tower fire prompted the most significant reform of building safety regulation in the United Kingdom. In response to the findings of the Grenfell Tower Inquiry, Parliament enacted the Building Safety Act 2022, which established a new Building Safety Regulator and imposed enhanced responsibilities on developers, building owners, designers, and contractors throughout the lifecycle of higher-risk buildings. The legislation created protocols to identify unsafe cladding, fund remediation efforts, and add accountability to the construction industry. The United Kingdom has also implemented remediation programs to remove unsafe cladding systems from residential buildings and improve oversight of building safety risks.

Australia

Australia undertook notable regulatory reforms following a series of high-profile cladding fires and growing public concern. In 2017, the Australian Senate initiated a review of combustible cladding and building product compliance and identified deficiencies in product certification and quality assurance processes, and regulatory oversight. Since then, Australian federal and state authorities have implemented building audits, risk assessment programs, remediation initiatives, and strengthened compliance requirements for façade materials. These efforts have focused on identifying buildings containing combustible cladding and reducing the risks associated with non-compliant exterior wall systems.

Liability and Insurance

Composite panels with combustible components have contributed to significant losses in fires across the world. The combustible components in these panels have supported and contributed to rapid fire spread. Composite panels tend to be a favorable choice for construction for the following reasons:

• Thermal insulation properties curb heat and cold
• Ability to muffle sound
• Light weight, easy construction
• The exterior enables quick washing
• Lower costs compared to other materials like foamed glass, glass fiber, and mineral wool

Since 2020, insurers have increased scrutiny of buildings containing combustible cladding. Underwriters frequently require detailed information regarding façade composition, remediation status, fire protection features, and compliance with applicable building codes. Buildings containing combustible cladding may face increased premiums or deductibles until remediation has been completed.

As, such insurers prefer mineral wool panels because they can contain the spread of fire. Unfortunately, mineral wool panels are not recommended for cold storage facilities, they cost more, and they are significantly heavier than other materials. While combustible-core panels tend to be a popular choice, these panels come with a slew of serious fire risks. Combustible panels can contribute to the potential rapid spread of fire, creation of dense and toxic smoke, the production of liquid fire from melting cores, all of which make the fire more difficult to fight.

To mitigate the risks of building with combustible core panels, insurers suggest that insureds:

• Identify and log every panel core in the building, along with fire ratings
• Frequently check for damage to the panels
• Work to replace combustible panels with non-combustible panels
• Install a sprinkler system
• Install heat and smoke detectors to be monitored off-site
• Avoid placing or storing flammable materials or electric cables near panels

Insurers should consider whether or not insureds are proactively minimizing their own risks as opposed to relying on insurance in case of emergency. Further, operators using combustible panels should have a carefully cultivated risk management plan for the building and its operations. For those working with combustible-core materials and applying for a new business insurance policy, it may not be uncommon for insurers to refuse a quote on the risk. In many cases, the unapproved types of combustible panels are rejected by insurance companies and the cost of replacement to approved types is substantial. In any case, the cost of replacement is nothing when compared to the cost of damages that may ensue from a rapidly spreading fire resulting from construction with hazardous, combustible materials.

In March 2019, the Kensington and Chelsea council was given a €24.5 million building insurance payout for a “recovery program” for those affected by the fire and the local community. The insurance payout from the Grenfell Tower fire was expected to be one of the most complex payouts in industry history; however, experts question whether the payout was enough.

Litigation

Litigation over combustible cladding has shifted from isolated product claims to disputes over remediation costs, professional negligence, product representations, and allocation of responsibility among construction participants.

Owners Corporation No. 1 of PS613436T v. LU Simon Builders Pty Ltd (Lacrosse Tower Litigation) (Victoria Court of Appeal, Australia 2021)

Following the 2014 Lacrosse Tower fire in Melbourne, the building owner sought recovery of remediation costs arising from the installation of polyethylene-core aluminum composite cladding. The court held that the builder was entitled to recover damages from the architect, fire engineer, and building surveyor, whose professional negligence contributed to the specification and approval of non-compliant cladding. The decision is a leading authority on the allocation of liability among construction professionals for combustible façade systems and resulting remediation costs.

Howard v. Arconic, Inc. (2019)

Arconic investors alleged that the company’s combustible panels were sold for high-rise buildings, including the Grenfell Tower, and provided misleading statements regarding the safety of the panels. The claims linked the company to the tragic fire that killed 78 individuals. Rather than proceed to trial, the court agreed to a $74 million settlement to resolve allegations that the company made misleading statements to investors.

Grenfell Tower

The Grenfell Tower fire generated extensive litigation against product manufacturers, contractors, and other entities involved in the tower's refurbishment. Claims have included wrongful death, product liability, and negligence allegations against companies associated with the cladding, insulation, and appliance systems implicated in the fire. The litigation continues to shape standards for product safety, corporate accountability, and risk allocation in the construction industry.

The Grenfell Tower fire in London slowly produced a series of lawsuits that may determine how insurers and panel-manufacturers proceed in the future. While we may not know the extent of the insurance payout for years to come, the panel manufacturer responsible for the fire faced an immediate investor lawsuit over the incident. Recently, three U.S. companies, Arconic, Inc., Celotex Corporation, and Whirlpool Corporation, were handed wrongful death and products liability lawsuit for products related to the Grenfell Tower fire. The suits include 143 counts of wrongful death and product liability complaints.

Future Outlook

The deadly fire at the Grenfell Tower brought to light the issue of using combustible-core panels in high rise construction. Localities have sought to improve fire testing measures and instill preventative measures to prevent future fires. Specifically, experts are suggesting the addition of non-combustible skins to high rise buildings as a preemptive measure in case of emergency. Without a centralized regulating authority, it is almost impossible to know where and when combustible panels have been installed.

Future efforts will likely focus on:

• Continued remediation and replacement of combustible façade systems
• Enhanced façade testing and performance standards
• Increased use of non-combustible construction materials
• Greater accountability among developers, manufacturers, and building owners
• Improved building inventories and regulatory oversight
• Expanded insurers and lender scrutiny of building safety risks