The Church of Scotland offices are located in the centre of Edinburgh, Scotland (in the New Town) at 121 George Street. These imposing buildings are popularly known in Church circles as "one-two-one". They were designed in a Scandinavian-influenced style by the architect Sydney Mitchell and built in 1909-1911 for the United Free Church of Scotland. Following the union of the Church of Scotland and the United Free Church of Scotland in 1929 the church offices were henceforth used by the newly united church. A matching extension, incorporating a ground floor bookshop, was built in the 1930s on the east side (119 George Street). A proposed matching extension on the west side (replacing the still-existing buildings at 123 George Street) was never built. 123 George Street is, however, owned by the Church of Scotland and has been incorporated into the offices.