Outline planning permission for a replacement house was granted in 2006. Detailed plans for a new house designed by Knox Bhavan Architects were granted planning permission in September 2008 and subsequent refinements were approved in March and September 2009. The final plans can be seen here. ("Accept" the licence agreement; then enter reference 7/2009/2177; then look for plans under the "Forms, Plans & Decision Details" tab.)
An artist's impression of the initial design is shown in these pictures. Construction started in September 2009 and was largely completed by April 2011.