This week, the Inquiry heard how the National House Building Council (NHBC) approved Kingspan’s combustible cladding insulation for many years. John Lewis, a fire engineer at the NHBC, admitted that a desire to collaborate with industry was a “corrupting” influence on their actions. It was also revealed that two days after the Grenfell fire, a senior civil servant asked the NHBC to support in public the government’s assertion that Grenfell Tower’s cladding was not permitted in the UK. Diane Marshall, who held final responsibility for approving building materials at NHBC, repeatedly defended the institution’s actions. Presenter: Kate Lamble Producer: Nathan Gower Researcher: Ben Henderson Studio Mix: Gareth Jones Editor: Hugh Levinson