Final costs associated with the new parliamentary building, Portcullis House, at Westminster are still unknown according to a report to Parliament by the head of the National Audit Office, controller and auditor general Sir John Bourn. The House of Commons is still in talks with London Underground over knock-on delays caused by Jubilee Line Extension work below the site at Westminster station. The delays have cost the Commons £3.1M so far in compensation to its own contractors who were unable to start work because of a late handover of the site by LU. Overall, Portcullis House building costs were £233M, an overrun of £85M. Legal costs and compensation to cladding contractor Harmon, which won a court battle to prove its tender was rejected unfairly, have amounted to £9.9M. The NAO is investigating the Portcullis House construction project and is to report later this year.