The Roaring 20s was a new era for Dame Allan's Schools. In 1921, a new governing document changed the name of the Schools from Allan's Endowed Schools to Dame Allan’s Schools. It was purely a formality as this was the names by which the Schools were already commonly known, but it foreshadowed what would become an even greater change just a few years later.

By this time, it was apparent that the site at College Street was rapidly proving out-dated and that the Schools were in need of space to expand their facilities. The Board of Education inspection report in 1926 made this particularly clear: "The utterly cramped condition of the buildings sorely restricts the corporate life of the School. The early provision of new and up-to-date premises is a matter of vital importance to the success of the School."

Having identified a new site for the schools in 1927, the governors purchased the land in Fenham, where the Schools are now sited, and an appeal to raise funds for the buildings was launched by Archbishop William Temple in 1928.