A large addition around 1802 by Francis Johnston gave the house its current form today. This is the latter day surviving Farnham House, which is now incorporated as the centrepiece of a hotel complex design. A large part of the original house having been demolished in the 20th century – in the topmost illustration, the entire left hand part of the house is now gone. In 1961, dry rot was discovered within the house and in an attempt to alleviate it, the oldest part of the house and the additions made to the house in 1839 were demolished. The Metropolitan Museum of Art has drawings by James wyatt from around 1790 for ceiling designs for Farnham. It is unclear if they were ever executed.