The mansion is built of ashlar faced with Totternhoe stone with a castellated parapet and low-pitched slate roofs. It features a variety of casement windows including pointed arch and ogee lights typical of the early Gothic Revival style. Before his untimely death, James Wyatt completed the north-facing front entrance and the central block, containing the state apartments and western courtyards. Jeffry Wyatt added private apartment blocks at an angle to the main building and an orangery with a turret in 1815–17. The main entrance features a projecting porte-cochère and octagonal turrets, added by Jeffry Wyatt c.1814.