The number of high-rise tower blocks with dangerous cladding could be more than double the official figure, the Royal Institution of Chartered Surveyors has claimed.

Government figures show there are 323 buildings over 18 metres with ACM cladding, of which 138 are privately owned residential buildings, including hotels and student accommodation. But speaking at the Royal Institute of British Architects fire safety conference, a senior member of RICS said many private block owners have not disclosed they have aluminium cladding similar to that used on the Grenfell Tower.

Gary Strong, director of practice standards and technical guidance at RICS said he believed this was due to concerns over share prices and valuations, with properties being downgraded “because of the blight factor.” “Out of the 323 buildings which were in the latest MHCLG report that have ACM cladding we know that in reality it’s more like double that. In the private sector, some of those have not been properly disclosed yet, with very good reason, because it will affect their share prices.” “We need to address the uncertainties in the market, we need to come together as professionals to try and make sure that we learn from other countries like the United States and Canada.” There have been reports in the media of flat owners seeing the value of their homes slashed by as much as 90 per cent, with many having bought their homes in the past couple of years using Help to Buy loans funded by the taxpayer.