The house was built in 1860 for James Cummings, dental surgeon, and was originally a single fronted house of four rooms. It was six rooms with garden by 1867 and then in 1870 it was extended sideways to its current size. The Rate Books described it at this time as eight rooms, double drawing room and bathroom. In 1883 Cummings sold the house to George Hamilton Dougharty, landowner and stock and station agent, who named it Cadzow (from the Celtic, "cadihou", meaning "beautiful castle") after the town in Scotland where the Dougharty family house, Fairhall, was situated. The Dougharty family remained in the house until 1952. In the early 1900s one of Dougharty's daughters was headmistress at the nearby Trinity School which was located in Trinity Hall behind Holy Trinity Church. In 1952 the Doughartys sold to William Robert Johnston, antique dealer and collector. He changed the name of the house to the more euphonious Fairhall and made many alterations both inside and out. Originally, on the western side of the front door was a three part window which sat centrally to the two windows above it; this was replaced by two single windows placed directly below the upper windows, giving a more symmetrical appearance. All the windows were reglazed to create Georgian style twelve paned windows, and a Georgian fanlight replaced the original. At first Johnston let the house as flats, but later lived there himself until his death in 1986.