John Stevenson, a successful pastoralist, stock and station agent and a Member of the Queensland Legislative Assembly, bought Fernberg in the mid 1880s and commissioned architect, Richard Gailey in 1888 to design extensive additions and alterations to the house. The scheme was a major undertaking which more than doubled the size of the original house, and altered the building from an 1860s villa to an Italianate Mansion. The new section had stuccoed detailing, faceted bays and the main entrance was orientated northwards and marked by a tower. These additions made the residence very close to the road; however following the "straightening" of Fernberg Road, the original road became the driveway. The road was transformed into a winding avenue that led to both the front and side entrances. In 1890 a fountain, gates and gate pillars were erected in the grounds that were well established with trees and shrubs. Various other outbuildings and structures were also developed on the property and included: a coach house, five stall stable, harness room, tool room, man's room, laundry, gymnasium, aviary, fowl house, closets, bush house, glass house and asphalt tennis court. The 1890s economic depression brought an end to Stevenson's fortune and by 1895 the property was mortgaged to William Pattison and Walter Russell Hall. Two years later Hall, a well-known philanthropist who had made his fortune from gold at Mount Morgan, took possession of the residence; however, he chose never to live at the property.