Exterior
The surviving portion of Bettisfield Park is a substantial Georgian country house of 2 storeys and basement, of scribed render over an ashlar plinth, hipped slate roofs behind low parapets on moulded cornices, and brick stacks. Of roughly L-plan, it has a S-facing entrance range and W-facing rear wing, with courtyard at the rear. The 6-bay entrance front is asymmetrical. To the R side are 3 equal bays incorporating a central entrance. To the L of centre is a wide full-height bow with domed roof, with 2 equal bays further L. The entrance has a Doric portico reached up stone steps between panelled piers. The portico has square outer columns, fluted inner columns, entablature with triglyph frieze and pediment with re-introduced coat of arms. The entrance, in a moulded architrave, has half-glazed panel doors with margin glazing, and overlights with similar detail. Floor-length windows in the lower storey are in arched recesses with panelled aprons in the plinth, stone entablatures with guttae over notional pilasters, and roundels in the tympana. Bays flanking the entrance have 15-pane hornless sashes, but the other bays have replacement cross windows. In the upper storey, where there is a continuous sill band, are 9-pane hornless sashes.
The 4-bay asymmetrical L (W) garden front incorporates a wide full-height bow on the R side, which is the end of the entrance range, and a rear wing with balancing advanced bay to the L end under a hipped roof. The bow and narrower central bays have cross windows in the lower storey similar to the front elevation, and the L-hand bay has a tripartite 15-pane sash window in a similar but wider opening. The bay L of centre has added steps. The upper storey has 9-pane sashes and sill band similar to the front.
The 3-bay R side wall of the main range, restored after C19 additions were taken down, has 9-pane sash windows and sill band in the upper storey. At the rear of the house the ground is lower and the building is entered at basement level. A hipped projection on the L side was rebuilt after the attached C16 and C19 parts of the building were demolished. It incorporates a large segmental-headed stair window. Set back in the centre is a panel door to the basement offset to the L, R of which are sash windows, 6-pane in the basement, 12-pane in the lower storey and 9-pane in the upper storey. On the R side the rear wing has upper-storey and basement sash windows in the side wall. In the end wall, also rebuilt after sections of the house were taken down, two 9-pane sash windows flank a blind window in the upper storey, and the basement has similar windows. Set back to the L is a basement door, 15-pane sash window in the lower storey and 9-pane window above.
Attached to the NW end of the rear wing is an L-shaped garden wall, which also retains the lower courtyard behind the house, mainly of brick with stone coping, the return section of which has a pointed doorway. Next to the house the wall incorporates an ashlar projection with 2 round-headed niches and panel to the centre. This was originally the plinth of a NW wing.