A slate-roofed six-room stone cottage in Georgian style was the first house built in the grounds of solicitor George Allen’s Toxteth Park Estate after Toxteth House. It was once known as Toxteth Cottage and its construction date may be as early as 1840. Wing additions were made in the 1880s and 1910.

By 1857 it was occupied by Allen’s daughter Mary Emma Lucy who the previous year had married architect George Allen Mansfield. It was the birthplace of their children Lucy in 1859 and Harold in 1861. The boy survived but Mary Mansfield died less than a week after his birth.

It was during the occupancy of George Allen’s eldest daughter Jane Elizabeth Pitman and her husband Wesleyan missionary and philologist William Binnington Boyce that the house acquired the name Tranby. The couple made the cottage their home after returning in 1877 to Sydney from London where they had lived for several years.

Tranby remained in the possession of the Boyce Allen family until 1946 when it was purchased by the Australian Board of Missions (ABM). It was gifted to Anglican bush brother Alf Clint by the Reverend John Hope of Christ Church St Laurence. As the ABM’s Director of Co-operatives in Australia and New Guinea, Clint had helped establish successful indigenous co-operatives throughout the Torres Strait, New South Wales and Queensland. In 1957 he set up Tranby as a training centre for indigenous people under the control of the ABM Christian Community Co-operative. The next year saw the foundation of the Tranby Co-operative for Aborigines.

Extensions during the 1980s included circular buildings in desert tones at the rear of the original house. Tranby was added to the New South Wales State Heritage Register in 1999.