The roof is broken into many parts and covered with slate, mostly with terracotta ridges and occasionally copper. The guttering, rainwater heads and downpipes are all in copper and of consistent detail designed especially for the house. Internally the house displays a variety of architectural styles, from Edwardian, Classical Revival to Art Nouveau and early Art Deco. The ground floor principal rooms comprise entry hall, stair hall, dining room, drawing room, ballroom/billiard room with attached bays and attached library/smoking room. All of these, with the exception of the drawing room, are heavily paneled in English oak and Queensland maple with finely detailed door cases and beamed ceilings. The plaster ceiling panels between the beams show bold Art Nouveau decoration and in the main rooms the ceilings show a subtle curve down towards the wall around the perimeter. The drawing room is entirely painted, even though it contains extensive areas of carved timber. Walls are paneled in a Classical Revival manner, reminiscent of the eighteenth and early nineteenth centuries with carved door cases and a strongly articulated dado. The alcove to the fireplace is entered through a large columned opening and contains a fine white and green serpentine marble chimneypiece. The stair is heavily carved in the Art Nouveau style with large newel posts at each change of direction. The lower posts now support modern white ball light fittings. The other ground-floor rooms display varying degrees of lesser decoration down to the minimal work in the south-west servants' wing. The principal bedroom and dressing room are finished in a similar but simpler manner to the drawing room and without the wall paneling. The other rooms show clear differentiation between family/guest use and servants' use in their scale and detail. The hospital use has introduced a lift adjacent to the ballroom and an upgraded dumb waiter adjacent to the kitchen. The joinery, including door and window hardware has been moved around in many instances. As at 1 July 1999, the physcial condition is excellent. Although in the 1830s Macdonald did not build a house on the site he was responsible for a considerable amount of landscaping including the planting of a vineyard on the site of what is now Wiston Gardens, including No. 4. The vineyard was reputedly designed by Thomas Shepherd, the first nurseryman and landscape designer in the colony. The Mount Adelaide Estate was extensively sub-divided between the time Macdonald departed for England in 1837 and the turn of the century.