The Middlesex Guildhall, built between 1912-1914, has been converted and renovated by Feilden+Mawson, as Architects and Technical Advisors, into the home of the newly created UK Supreme Court, which also houses the Judicial Committee of the Privy Council.

The project received Planning and Listed Building consent in 2006, with construction starting in 2007. It was opened by HM the Queen in October 2009.