Impact case study database

In the immediate aftermath of the Grenfell Tower fire, public opinion focused on the polyethylene-cored aluminium composite panels (ACP-PE) as a major cause of the tragedy. Hull appeared on broadcast media more than 20 times [A] explaining that the flammability of ACP-PE and combustible insulation foam had combined with disastrous consequences. Shortly afterwards, the UK’s Building Research Establishment (BRE) were instructed to undertake 7 tests using the BS8414 rig for the Department of Communities and Local Government (DCLG) on different combinations of ACP and insulation. The first two tests, using ACP-PE were stopped, before the insulation became involved in the fire, for safety reasons (as specified in BS8414), and the two tests with fire retarded ACP and combustible insulation were stopped after a little longer, again for safety reasons, so the contribution of the insulation remained unknown.

In September 2017, Hull and Stec were invited to present their findings, later reported in a peer-reviewed paper [2], showing the contribution of both insulation and polyethylene-filled ACP, to an All-Party Parliamentary Group, The Parliamentary and Scientific Committee. This was followed by a report in the Parliamentary Office of Science and Technology POSTNOTE [B], which brought our work to the wider attention of MPs and peers.

In February 2018, Stec was appointed to the Review of Building Regulations chaired by Dame Judith Hackitt as a member of Working Group 6 Products and Classification, and outlined our work, showing that changes to the building regulations were necessary. The Working Group concluded that revision was required of the test standard that allowed combustible materials to be used on tall buildings (BS 8414) [C].

In June 2018, Stec was also appointed as an Expert Witness to the Grenfell Tower Inquiry where she continues to investigate the effect of combustible materials on the tragedies that unfolded on the night of the fire. The progress of the Inquiry has been delayed due to the Covid-19 pandemic [D].

Hull and Stec have also independently reported their research to the All-Party Parliamentary Group, Fire Safety Rescue, to a separate audience of MPs and peers, and also to the Local Government Association, in person to its Chairman, Lord Porter of Spalding, and his team. The results were also presented to the Royal Institute of British Architects (RIBA) Expert Group on Fire Safety who presented their conclusions to the Parliamentary Select Committee on Communities, Housing and Local Government [E].

The work with the Fire Protection Association on combustible façades was reported directly to civil servants in the Ministry of Housing, Communities and Local Government (MHCLG), responsible for fire regulations in buildings, and published online before the announcement of the ban on combustible materials on tall residential buildings [F]. After our results had been reported to MHCLG, the Minister for Housing, the Rt Hon James Brokenshire, announced the ban on combustible products on all high-rise residential buildings. That ban came into force in December 2018. However, the problem of combustible facades on existing tall residential buildings is massive, and remediation will take time. The government has pledged GBP3,500,000,000 to remove combustible cladding from all the 12,000 residential buildings over 18 metres and to provide loans to support remediation in the 77,500 residential buildings between 11 and 18 metres. Overall, 839,000 people are believed to live in buildings over 11 metres with some form of cladding [G, H]. From January to May 2020, the MHCLG consulted on a proposal to increase the scope of the ban to cover all buildings over 11 metres, the outcome is still awaited (March 2021).

The fire hazard of another form of combustible cladding, High Pressure Laminate (HPL), which is cheaper, and approximately 3 times more prevalent than ACP-PE on high-rise buildings, was shown in our paper [2] to have a much higher heat release and shorter ignition time than ACP-PE, and contributed to the 6 deaths in the Lakanal House fire in July 2009. In January 2019, Hull highlighted the risks of fires, similar to Grenfell, in HPL clad buildings [I]. In March 2019 the Government announced plans to undertake limited testing of the safest fire-retarded form of HPL, backed by non-combustible insulation, in the BS8414 large-scale scenario [J]. In January 2020, Hull’s research helped inform a legal case by Leigh-Day Solicitors, who were preparing an action against the government for failing to protect the occupants of HPL clad buildings. As a result of increased awareness of the risks posed by HPL cladding from Hull’s research, in May 2020 the Housing Secretary, Rt Hon Robert Jenrick, MP, announced that the government would release a further GBP1,000,000,000 to replace unsafe non-ACM cladding. This is predominantly combustible HPL cladding [K].

As a result of our research and the changing regulatory landscape there has been a decline in the use of combustible materials and an uptake in non-combustible alternatives on building exteriors. In a survey, the number of UK architects expecting PUR/PIR insulation usage to increase fell from 45% in 2016 to 17% in 2020, while over the same period, for glass wool insulation, usage expectation increased from 11% to 23%, and for stone wool insulation it increased from 21% to 37% [L, M ]. Similar figures were reported for other European countries. In the UK the market share of non-combustible insulation has increased significantly, with a corresponding decrease in plastic foam. The Rockwool Group reported in their 2018 annual report that “The focus on stronger fire-safety regulation affected the UK and Polish markets, contributing to greater demand for non-combustible stone wool building materials.” [N]