The American Embassy was sold in 2006 for £500 million to be relocated south of the Thames. In 2013, the Canadian Embassy sold its Mayfair building for £306 million. Both buildings are to be converted to provide high-end residential apartments. And others diplomatic properties have been sold in recent years, most of them because of Security issues, historic listed properties that can be difficult to upgrade and new technologies. Embassies prefer efficient office space and high secured buildings.