He and his wife Esther Baum Born (1902−1987) collaborated on diverse projects in the San Francisco Bay Area from 1936 on.

[1][2] Ernest was born in San Francisco, Esther in Palo Alto, and they married in 1926 after meeting at UC Berkeley's architecture school.

After graduation he traveled to Europe on a Guggenheim Fellowship, then returned to UC Berkeley earning a master's degree in 1923, with a thesis on the relation of painting to architecture.

Ernest spent time as a draftsman at Shreve, Lamb & Harmon, designers of the Empire State Building.

Born designed the "Main Portal", a monumental entrance consisting of five staggered volumes each at the left and right site of a central passage.

1951, in collaboration with architect Henry H. Gutterson, Born designed North Beach Place, a public housing project at the cable car turntable on Taylor Street.

[9] In 1975, a collaborative project between Born and Lawrence Halprin resulted in the United Nations Plaza Fountain.

In 1950, Born designed the Pacific School of Religion, a seminary located north of the UC Berkeley campus.

[14] Born also designed the house of Walter Horn, who he later collaborated with to write and illustrate texts on medieval architecture.

[4] His drawings for a proposed United Nations Center, with William Wurster and Theodore Bernardi, were exhibited in San Francisco and New York museums.

[17] During the war years, Born worked with architect Gardner Dailey on special military projects in Brazil and in the U.S.[4] The Borns' 1958 vision for "Embarcadero City" for the San Francisco Port Authority, a master plan for the waterfront from the Ferry Building to Aquatic Park that would have replaced most existing structures with new buildings and piers with landfill, was never built.