He studied fresco painting in France before returning to the United States, where he worked for a period at architectural firms in New York City and at Colonial Williamsburg.

After a period of work alongside Victor N. J. Jones in the late 1940s, he moved to Hawaii, where he designed many of Honolulu's early high-rises as the resident architect of John Graham & Company.

[1][2][3] He became one of the main contributors to the emerging Northwest Regional modernist style, with work featured in a variety of contemporary architectural publications such as Pacific Architect & Builder.

[3] Jacobsen was nominated for and received a Langley Scholarship from the American Institute of Architects in 1938, with which he traveled across Scandinavia studying housing developments; this would go on to strongly influence his architectural philosophy.

From 1939 to 1942, he worked alongside a wide group of other local architects in designing Yesler Terrace, the first racially-integrated public housing project in the United States.

After this, he returned to working with Victor Jones, with whom he designed the Bannock County Hospital in Pocatello, Gerberding Hall at the University of Washington, and the Richmond Highlands branch of the Seattle Trust & Savings Bank in Shoreline.

[2] He moved with his family to Hawaii during the 1950s, where he became the resident architect of John Graham & Company, with whom he designed the Ilikai Hotel and the Ala Moana Shopping Center.

He worked with developer Lloyd Martin to construct a number of Honolulu's early high-rises, including the Admiral Cook Apartment Hotel in Waikiki.

He then returned again to private practice in the late 1960s and 1970s, designing the research facilities of Sea Life Park Hawaii, and the retirement home of aviator Charles Lindbergh in Hana, Maui.