On the death of James Dormer in 1741, unmarried and without issue, the estate passed to his first cousin Sir Clement Cottrell-Dormer(1686–1758) (the son of his aunt Anne Cottrell) who added the surname Dormer to his patronymic. At this time Kent also embellished the house itself, with crenellations and two wings containing a drawing room and a "delightful" library, according to Horace Walpole who said of Rousham in 1760 "it reinstated Kent with me; he has no where shewn so much taste". The interiors were altered a century later but the hall, the principal room of the house, has survived alteration by successive generations unchanged, and remains as completed in the 17th century. Kent's exterior work is today almost as built, but in 1876 the original octagonal paned glazing was replaced with innovative large sheets of plate glass, during a heavy-handed restoration of the house by the architect James Piers St Aubyn. The house contains fine collections of Jacobean and 18th-century furniture, paintings and statuary, all displayed in a domestic setting.