 In 1909 Rooke designed a four-story addition to the 1903 stable, giving it an electric freight elevator and a new facade topped with a Mansard roof.Purity of milk became of increasing importance to the public and that impacted the design of Sheffield's plants.In 1910, Horton explained that increased costs of his bottled product were tied to ensuring sterile conditions and the following year he asked Rooke to design a second plant for him.