The building was to a design by Joseph Spark, completed by architects Ross & Richardson of Darlington.
[1] It is constructed of coursed squared stone and has a roof of Welsh slate; the building consists of a two storey centre section with Venetian style entrance, with two single storey wings.
[1][4] The building was later used as a store, and to repair wagons, as well as being used as a rifle range by the railway company.
The North Eastern Locomotive Preservation Group (NELPG) took over the west wing in 2002.
[1] The New Build LNER Class P2, is being built here by the same people that created Tornado.