While based in Charlottesville, Lerner led his own firm, Ralph Lerner, Architecture and Urban Design.[3] From 1979 to 1980, Lerner taught at Polytechnic of Central London.[1][2] He returned to the United States for a position at Harvard, then accepted an associate professorship at Princeton University in 1983.[1][2] Ralph Lerner Architect PC was established in Princeton the following year.[1] He was appointed dean of the Princeton University School of Architecture in 1989, two years after becoming a full professor.[1][2] Lerner was designated George Dutton โ27 Professor of Architecture in 1994, and was succeeded as dean by Stan Allen in 2002.[1] Lerner remained on the Princeton faculty until his 2008 resignation, to assume the deanship of the Faculty of Architecture at the University of Hong Kong.[1][2]
Lerner resigned from HKU in April 2011 for health reasons,[1][3] and returned to the United States. He died in Princeton, New Jersey, of brain cancer on May 7, 2011, aged 61.[1][3]