The government’s building safety experts warned last year that the drive for greater energy efficiency meant more and more buildings are being wrapped in materials that could go up in flames. In a report compiled before the Grenfell Tower disaster on Wednesday, the Building Research Establishment, which works for the Department of Communities and Local Government on fire investigations, said attempts to innovate with insulation were leading to an “increase in the volume of potentially combustible materials being applied” to buildings. Construction and fire experts increasingly fear that the cladding system applied to Grenfell Tower may have been instrumental in spreading the fire.