In 1916 Grant founded a separate Montessori unit for pupils from 2 to 8 years of age. The initial location is unclear, but in 1924 moved to Kingston Lodge, adjacent to the school grounds. (Kingston Lodge later became Goddard House is now the music school.) In 1932 the school was renamed to St George's Children's House to attract larger numbers. Its business interests were formally merged with the main school from 1949. In 1955 it broke ties with St George's and moved to Gorselands near Harpenden common.