Former Postillions House at South-East Corner of Stable Yard

The Former Postillion's House, located at the south-east corner of the Stable Yard, was built in 1873 by Alfred Waterhouse for the 3rd Marquis of Westminster. This three-storey building is constructed of buff stone and features a roof made of graded grey slates, which forms a truncated pyramid with dormer gables at the base. The house has two windows and is connected to the Chapel by a two-storey wing that includes an arcaded passage on the lower level.

Notable architectural elements include leaded corner spirelets, two symmetrically placed banded stone chimneys with circular flues (the larger one located to the north), and octagonal corner buttresses. The windows are distinguished by shaped mullions and transoms, along with patterned leaded glazing. There are central half-dormers on the south, east, and north sides, with the southern half-dormer featuring carvings. The west side has two full-dormers, one of which is also carved.

Access to the house from the former Hall is through the chapel narthex and the arcaded passage, while entry from the stable yard is via a porch with a pentice roof. The east side of the building shows evidence of a demolished wing. Designed in a 16th-century chateau style, the house and the Chapel were intended to serve as the northern wing of the former Hall, visible from the garden to the east and the entrance court to the west. The interior has not been inspected.