Betteshanger House Northbourne Park School

House built between 1856 and 1886 by George Devey, with alterations and additions made around 1893–94. Built for Sir Walter James, first Lord Northbourne. The house is constructed of brown brick and flint with ragstone and Bath stone dressings, and includes some brick diapering. It has a plain tiled roof.

The design employs an irregular, roughly L-shaped plan, with planning and stylistic variation deliberately intended to suggest the historic development of a medieval tower with a low Elizabethan wing, extended by a Jacobean gabled block containing state rooms. This visual narrative is actually a re-casing of an earlier bay-windowed barge-boarded villa built in 1829 by Robert Lugar.

The entrance front features a service wing to the right with four kneelered gables in two storeys, part of the 1893 additions. The centre-right contains a four-storey tower with an adjoining three-storey canted bay, beside a two-storey central block. A projecting gabled porch with oriel windows contains the entrance, now blocked. The main range at the end left comprises two storeys with three Dutch gables and a central two-storey bow. Tall chimney stacks in clusters range along the roofline, with a wooden cupola over the tower. Mullioned windows throughout feature frequent carved panels and heraldic crests, with a carved panel over the present arched entrance to the right of the porch. The left return of the end block has two Dutch gables, each with projecting two-storey canted bays, the left one sporting a Venetian-style window and portrait bust in a rounded niche.

The garden front more clearly reflects the supposed history of the house and uses varied materials to suggest rebuilding and alteration. The main block to the right has two irregularly sized Dutch gables with mullioned and Venetian-derived windows. An entrance in such a composition appears on the ground floor of the left-hand block, with oriels above, tucked into a re-entrant angle to the right. A lower two-storey section to the centre features a two-storey barge-boarded projection; the gable is enriched with interlacing plasterwork. The re-entrant to the "James Tower" contains a two-storey bow. The tower has a stone base with flint and brick diaper work in the upper sections, and an octagonal stair turret. All features include mullioned and transomed windows throughout.

The interior contains a main hall and staircase hall with lozenge-panelled wainscotting and enriched fire surrounds with doubled Ionic columns. Screens feature strapwork with elliptical arches to the stairs. The stairs are in early 18th-century style, on a half-landing plan with turned balusters, wreathed and ramped handrail, and enriched brackets. Upper landings are lit from above and feature plaster-enriched ceilings and painted glass. A second, less ornate but similarly styled staircase includes an arcaded gallery. The dining halls form part of the 1893–94 alterations, featuring a turned-baluster stair with enriched newels at the lower end, leading to an arcaded gallery with strapwork enrichment and a pedimented aedicule door surround. A large columned fireplace includes a framed painting in the upper stage and heraldic arms. Most other contemporary interior features survive, including painted glass, mosaic floors, plastered and ribbed ceilings, fitted library shelves, and several stone and alabaster plaques in recesses.