A six storey mansion block located within the Westminster Abbey & Parliament Square conservation area adjacent to Government offices in the heart of London. PSL Engineers were commissioned by a private client to complete an inspection and report for reported cracking to a four-bedroom flat located on the second floor of the block. The building was constructed circa 1900 and comprises solid filler joist floors with load bearing masonry. There were various signs of movement to the main elevations, together with historical alterations to flats above and below. Through careful inspection and review of archive drawing information we were able to identify the causes of cracking.