Walter F. Ballinger an architect and engineer in Philadelphia, Pennsylvania, and then spent two years traveling in Europe, giving particular attention to architectural designs.

Among these are the Manila Cathedral; UST Central Seminary; the Arguelles, Paterno Building FEATI University at carriedo corner McArthur Bridge, Sta.

Andres P. Luna; and Fernandez buildings; the Assumption Academy of Pampanga, the North Syquia and Admiral Apartments (demolished 2014 during Mayor Joseph E. Estrada Administration) in Malate, and the residence of Mr. Joaquin Baltazar, the latter having taken the first prize in the 1930 beautiful home contest.

In 1929 and 1930 Ocampo was a member of the Board of Examiners for Architects in Manila, co-founded Philippine Institute of Architecture (PIA) together Ar.

Andres P. Luna and in addition to his private practice he became a member of the faculty of the School of Architecture at the University of Santo Tomas, Manila.