Williams's interest in churches led to his choosing a career in architecture, and he was trained by Alexander North, then architect to the Diocese of Tasmania.
His primary client was the Anglican Church; for many years he was diocesan architect for both Bathurst, where he enlarged the cathedral,[2] and Grafton; he was advisory architect to the Chapter of Goulburn Cathedral, and designed buildings for every diocese in Victoria and also for the dioceses of Adelaide, North Queensland, Perth, Bunbury and for Devonport and Railton.
He advised on lighting, stained glass, metalwork, altar furnishings, plate, carved ornamentation, murals, opus sectile mosaics, and floor coverings.
[1] Williams also introduced innovations that increase the sense of space in his churches and make them more comfortable in the hot climate.
In World War II, when most building was suspended, he moved his practice from 108 Queen Street, Melbourne[3] to his home in Brighton.