Mansell joined the Philadelphia Chapter of the
American Institute of Architects, in 1942. He was elected a
Fellows of the American Institute of Architects in 1968 and was also awarded a NCARB Certificate. He practiced under his own name,
T. Norman Mansell, from 1938 to 1955. With
Richard Arnold Lewis and
Edwin Lindsay Fugate, Thomas Norman Mansell established
Mansell, Lewis & Fugate in 1955 and disbanded the partnership in 1969. The firm's address was 300 E. Lancaster Avenue
Wynnewood, Pennsylvania 19096. In 1970, he was registered to practice in
Delaware,
Delaware,
Georgia,
Kentucky,
Maryland,
Michigan,
Minnesota,
New Jersey,
New York,
North Carolina,
Ohio,
Pennsylvania,
South Carolina, and
Virginia. He was the president of Darby Lions Club, Pennsylvania, from 1932 to 1933, president of the Springfield Zoning Hearing Board from 1946 to 1970, president of the Philadelphia Sketch Club from 1963 to 1964, president of Delaware County Tuberculosis & Health Association, Pennsylvania, from 1970 to 1971. He was president of the Philadelphia Chapter of the
American Institute of Architects in 1961 and 1966, the 1st vice president in 1965, and director in and 1961, 1968–1970. He was the director of the
Pennsylvania Society of Architects from 1968 to 1970. ==Awards and publications==