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.
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.
The church offices also incorporate a chapel near the main entrance and a staff canteen in the basement.
The one major exception is the Social Care Council (CrossReach) which is located outside the city centre at Charis House, 47 Milton Road East, Edinburgh.