Howells served as president of the Society of Beaux-Arts Architects and the Society of Architects Diplômes. He was elected to the National Institute of Arts and Letters, named a Chevalier by the French Legion of Honor and an officer of the Order of the Crown (Belgium), and served on the U.S. Commission of Fine Arts from 1933 to 1937.
Howells held prominent roles in architectural organizations, including leadership positions within the Society of Beaux-Arts Architects and the Society of Architects Diplômes. He was honored with prestigious awards such as membership in the National Institute of Arts and Letters, a French Legion of Honor Chevalier title, and an officer position within the Order of the Crown (Belgium). Furthermore, he served on the U.S. Commission of Fine Arts from 1933 to 1937.