In November 2009, the U.S. government conditionally agreed to sell the lease of the Grosvenor Square Chancery Building to Qatari real-estate investment firm Qatari Diar, which in 2007 purchased Chelsea Barracks. Though the price was undisclosed, the lease's worth was estimated at £500 million in July 2000. The development value of the property was reduced when the building was given Grade II listed status, requiring developers to maintain its current design. The building is now one of Mayfair's 238 listed buildings and monuments. In 2016, plans were approved for the conversion of the building into a hotel.