He was educated at Allesley Park College, a boys' school, in Coventry, and at the age of 16 intended to pursue a career in the Royal Navy.

Owsley later claimed to have worked on projects designed by Matthew Digby Wyatt and George Gilbert Scott during his apprenticeship.

In 1869 he moved to Ohio, purchasing land in Weathersfield Township in Trumbull County near Youngstown, and opened an office as an architect in 1872.

His first major work was the second Mahoning County Courthouse in Youngstown, completed in 1876, and over the next decade developed a successful regional practice.

After an education at the University of Pennsylvania and the École des Beaux-Arts in Paris, the younger Owsley joined his father's office in 1905.