Mackintosh's contribution to 233 St Vincent Street consists of an extension to the existing offices which was commissioned in 1898 and finished by 1899. It was a minor commission consisting of an entrance hall and top lit offices beyond, a similar generic plan for to the Tea Rooms - which it predates. After checking with the Regional Archives at the Mitchell Library it was found that no original drawings have survived to the present day. Hence, the following photographs, survey notes and measured drawings are the only complete record of this interior