Milne founded the Aberdeen-based Stewart Milne Construction Group, a
housebuilding contractor, in 1975. He started off his business renovating bathrooms. Stewart Milne Group sold its timber frame manufacturing subsidiary to Fife-based James Donaldson & Sons (later
Donaldson Group) in 2021. In April 2022, the group announced that the housebuilding business was up for sale. In January 2024, the Scottish housebuilding business went into
administration with the loss of 217 jobs, due to "the slump in the oil-linked property market around Aberdeen and the firm's hesitance to buy land during Covid". The group's English subsidiary,
Manchester-based Stewart Milne Homes North West England (Developments) Ltd, also went into administration, on 12 January 2023, with
Homes England set to lose up to £9.2m as a result. The group collapsed owing suppliers and subcontractors £153m. ==References==