On November 29th 2018, regulations were laid before Parliament to give legal effect to the ban on combustible materials in external wall systems over 18m. On December 21st 2018 changes to the Building Regulations in England, and amendments to its associated guidance Approved Document B, came into effect.
See PDF for more information:
https://www.legislation.gov.uk/uksi/2018/1230/pdfs/uksi_20181230_en.pdf