Lange Leopold Powell (1886-1938), architect, was born on 2 July 1886 at Rockhampton, one of the children of William Powell, Methodist minister and his second wife Mary Ellen, née Zillman. Following his schooling, he was articled to Addison & Corrie, architects and attended Brisbane Technical College. He briefly worked for C. W. Chambers and the Public Works Department and went to London in 1908. There he worked for Belcher & Co. Powell married Maud Gertrude Moore at Murtoa, Victoria, on 19 April 1911.
His Brisbane partnerships included Chambers & Powell (1911-21), Powell & Hutton (1922-25) and Atkinson, Powell & Conrad (1927-31). The latter firm was appointed architect to the Brisbane and South Coast Hospital Board in 1926. St Martin's War Memorial Hospital (opened in 1922) is Powell's best-known work, and he himself considered it one of his best designs. He was grand architect for the Masonic Temple, Brisbane (1928).
Powell was an active member and office bearer of the Queensland Institute of Architects and the federal council of the Australian Institute of Architects. With Sir Charles Rosenthal he drafted the constitution of the Royal Australian Institute of Architects (1930). He died in 1938.