Born in Aabenraa, Jacobsen was the son of shipbuilder Niels Jacobsen and Marie Kjaer. Jacobsen initially trained as a bricklayer. In September 1884, he began his studies at the Royal Danish Academy of Fine Arts in Copenhagen, where he studied under Hans Jørgen Holm. Graduating in 1890, he was subsequently employed by Johan Daniel Herholdt, Ferdinand Meldahl, and Martin Nyrop. He opened his own design studio in Odense in 1893. From 1894 to 1908, he taught at Odense Technical College, served on the Board of Directors 1909-25, and participated in architectural competitions as a judge. Jacobsen was a member of the Odense City Council 1909-25, and chairman from 1911. He was honored as a Knight of the Dannebrog. Jacobsen was in Italy in 1891. He exhibited at Charlottenborg Spring Exhibition in 1898, the World Exhibition in Paris in 1900, the City Hall exhibition in Copenhagen in 1901, as well as the Kunstgewerbemuseum Berlin in 1910.