Hardenhuish House (Chippenham Grammar School)

This is a late 18th-century manor house, later altered in around 1829 and including a portico designed by Sir John Soane. It now functions as a school. The house is constructed of limestone ashlar with slate roofs; the front is hipped, while the rear wings have gabled roofs. Moulded ashlar stacks mark the rear and ridges of the wings. The architectural style is Palladian, with the portico in a Classical style.

The plan is of a double-depth central stair-hall, with rear wings and later additions to the left. The main front is symmetrical with five bays, the central three bays stepped forward and topped by a pediment. A table, possibly intended for an urn, sits atop the pediment, above a modillion cornice, platband and sill band to the first floor. Upper floor windows have moulded architraves; the second floor features 3/6-pane sashes, while the first floor centre has three pedimented 6/6-pane sashes flanked by windows with floating cornices. Steps lead to a semicircular, four-columned Ionic portico with an entablature and dentilled cornice, flanked by 6/6-pane sash windows with chamfered architraves. The returns have full-height splayed bays with windows similar to those on the front.

A mid-19th century service block to the left has a hipped roof and a splayed front with 6/6-pane sash windows flanked by 4/4-pane sashes, the left return being roughcast with freestone dressings and a moulded eaves cornice. This service block is connected to the main house by a mid-to-late 19th-century dining room with three large 6/6-pane sash windows. The splayed rear right return originally had a conservatory (likely dating to 1829); it now has full-height 9/9-pane sash windows. In the rear right corner are two octagonal rooms with hipped lead roofs, one having a ball finial. A block to the rear is capped with a hipped roof featuring a lantern.

Inside, the entrance hall retains a 18th-century modillion cornice and oak floorboards. A 19th-century semicircular arch leads to the rear stair hall, which houses a 19th-century open-string dogleg staircase with turned balusters rising to the top floor. The curtail step is double-wreathed. There are 19th-century double entrance doors with margin panes, 4-panel doors to the upper floors, and 6-panel doors on the ground floor. One ground-floor room retains a modillion cornice but has a high 19th-century skirting board.