Mental hospital built in several phases, original part by William Burn designed 1835 and opened 1.6.1839 (only north half executed of original conception of 2 linked cruciform-plan blocks); extended to south by William B. Moffat, 1867-71 approximately following Burn's scheme, but in T-plan, with South show front. Rear (east) dining wing by Sydney Mitchell 1903-4 extended for a board room and nurses' residence 1923-6
by J Flett, Clerk of Works. Numerous lesser alterations/additions, including some glazed verandahs. 3 storeys. All stugged red ashlar with polished dressings and band course between 2 lower-floors; windows are single or tripartite and have keystoned architraves; most have aprons and open or scrolled pediments at 1st floor.
Original building: essentially 4 arms in Greek cross plan radiating from octagonal 4-storey stair well, and canted in angles. Wings have terminal blocks (substantial north block with 9 north-facing bays), main west-facing entrance (re-modelled by Mitchell) in original south terminal. North-facing arcaded depressed-arched galleries to upper floors all now galzed.
Cornice; some pierced parapets. 1867-71 addition: elevational treatment similar to that of original composition; long south elevation: variety of planes in symmetrical composition, 3 inner bays with central porch, round-headed 1st floor windows with broken pediments, square windows above and elaborated parapet; 2 circular stair turrets on east elevation (larger by Sydney Mitchell 1900-1). Dining and board room extensions are plainer, and have pedimented dormers; steel fire escapes on latter. Slate roofs.
Interior: 2 principal stairs one in original and second in 1867-71 range both by Moffat each enclosed by decorative lattice cast-iron and lit by cupola; stair in former range is octagonal and supported on Corinthian columns at each level; dining room in Edwardian Baroque style with Ionic pilasters, elaborate friezes and coffered ceilings; much fine wooden panelling and ceiling plasterwork; some corridor ceilings barrel- vaulted; recreation room above south door converted (with movable partitions) to form 3 rooms, inner room with Corinthian pilasters below remaining gallery.