Estate Office Including 10 Castle Ashby

The Estate Office, including 10 Castle Ashby, is a coach-house that has been converted into an estate office, garages, and dwellings. It dates from the late 17th century to early 18th century and was altered in the 20th century. The building is a rectangular, two-storey, seven-bay structure made of coursed limestone rubble with limestone dressings and features a pantile roof along with stone end and internal stacks.

On the west-facing side, which looks towards Castle Ashby, there are plain ashlar pilasters that define the bays. The central bay and the bay to the left of the right end have 20th-century garage doors. The other bays feature stone cross windows with moulded stone surrounds. The roof has four gabled dormers and stone-coped gables with kneelers.

The irregular rear elevation includes a central panelled door with an overlight set in a moulded stone surround, flanked by wood mullion and transom windows with wood lintels. There are additional later doors to the far left and to the right of the centre, both with wood lintels, and the right door has a flat-arched head. Central doors are located at the gable ends, and there is a single-storey link to the left, likely from the 19th century, connecting the building to the stable block.

This building is depicted on an estate map from 1760 when it was a detached structure that formed part of a formal composition with the stable block, which then extended in a U-plan around the building, although part of it has since been demolished.