James Thomas Knowles (1806–1884)[1] was a British architect with an extensive practice in building upper-class houses in the Italianate manner more familiar in the work of Sir Charles Barry. His designs submitted in the competition for the new Houses of Parliament lost to Barry's design. In London, Knowles built the confident and technically assured palazzo at 15, Kensington Palace Gardens (1854).[2] Together with his son, (Sir) James Thomas Knowles (1831–1908), he was responsible for the Grosvenor Hotel.
His vast Italianate mansion at Silverton Park, Devon, for the fourth Earl of Egremont, who had inherited the title but not the great family seat, Petworth in Sussex, determined to build a rival structure. It was not fully complete when the earl died in 1845, and after a house sale in 1892 dispersed its contents,[3] it was demolished; only the stables remain.
One of his sketchbooks is in the library of the Royal Institute of British Architects.[4]
His son, Sir James Knowles (1831 - 1908), was an architect in partnership with his father, and editor of the Contemporary Review, 1870–77.