Werner Trumbower was born in Richlandtown, PA, the son of Lewis T. and Anna Trumbower. He graduated from Norristown High School in 1895 and entered the University of Pennsylvania with the Class of 1898, but remained only for two years. In 1896 he was employed as a draftsman by
Charles Balderston and from 1898-1899 in the same capacity by
Cope & Stewardson. In 1899 he launched his own firm and remained in practice in Philadelphia at least through 1916, later moving to Mahway, New Jersey. Trumbower's clients included such large companies as A. F. Bornot & Bros. and Wyeth & Bros.
Trumbower was a member of the Philadelphia Chapter of the American Institute of Architects (AIA).