 Howells moved to New York City and founded the architectural firm Howells & Stokes with Isaac Newton Phelps Stokes, who had also studied at the École.The partnership designed such works as St. Paul's Chapel at Columbia University and Stormfield, an Italianate villa commissioned by Samuel Clemens, a longtime friend of his father.Ending the partnership in 1913, Howells would focus his practice on office buildings in the Art Deco style, some of which he completed with Raymond Hood, whom he had met during his time at the École, and whom he had invited to become a partner when he was selected to enter the Chicago Tribune building competition in 1922.