Thornbury is a suburb which lies within the Territorial Authority of Southland, one of 43 residential suburbs which form the wider region. Thornbury is the 31st largest suburb of Southland in terms of the total number of residential housing stock. Thornbury provides a range of housing stock, with the earliest residential housing recorded in the area constructed between 1910 - 1919. The majority of the residential housing stock in the locality was constructed between 1950 - 1959. Residential housing stock in Thornbury is made up of approximately 80% residential housing and 20% lifestyle properties.