Preston began his career as an architect in the office of his father, Jonathan Preston, in 1861, having previously studied at Cambridge and at the Ecole des Beaux-Arts in Paris. He was the architect of many prominent buildings, including the Rogers Building of the Massachusetts Institute of Technology, the Massachusetts Charitable Mechanics Association Building, the Cadet Armory on Columbus Avenue, Boston University School of Law on Ashburton Place, thirty or more buildings of the Massachusetts School for the Feeble Minded, and the State Industrial School for Girls at Lancaster. He was elected an Associate of the American Institute of Architects in 1870 and a Fellow in 1884.

| period | name | type |
|---|---|---|
| American Institute of Architects | Fellow | |
| from 1870 | American Institute of Architects | member |
| from 1884 | American Institute of Architects | Fellow |