Local authorities have been asked to undertake a data collection exercise on residential buildings 18 metres and over in height to identify their external wall systems. Local authorities have powers under Section 235 of the Housing Act 2004 to require building owners to provide documentation which may include the type of materials on the external wall systems of buildings. Local authorities can pursue enforcement action against buildings that are hazardous through the Housing Health and Safety Rating System (HHSRS) regime.