From Ontario to Winnipeg, and Vancouver to Victoria, Thomas Hooper left an architectural legacy in every city he lived and worked. In 1889, he moved to Victoria, B.C. where his career and designs gave him the title as architect for numerous buildings in the city. These include the later additions to St. Ann's Academy; Centennial Methodist Church (1891); E.A. Morris, Tobacconist (1892); and the Royal Bank Building (1909), now Munro's Books; and Carnegie Library (1904).

In the 1890's, Hooper's architectural firm was briefly known as Hooper and Goddard. And by the early 1900's, he had gone into partnership with C.E. Watkins. In his early years of designing, Hooper was influenced by the American Richardsonian school of architecture (Martin Segger and Douglas Franklin. Exploring Victoria's Architecture. p. 297). This style is evident in the Metropolitan Methodist United Church (1890), in Victoria, B.C.

At the same time that Hooper was practicing in Victoria, he maintained another office in Vancouver, B.C. Most notably, he is remembered for designing the Spencer Building and the rear addition to the Vancouver Courthouse. Hooper ended his career in Victoria and Vancouver in 1915, to pursue his interests in New York. There he built a skyscraper and stayed until 1927. Thomas Hooper returned to Vancouver where he died in 1935 (Martin Segger and Douglas Franklin. Exploring Victoria's Architecture. p. 297).