He graduated from the Royal Institute of Technology in Stockholm in 1914, and worked at the Norwegian Museum of Cultural History in Oslo from 1918 to 1927.
From 1927 he was a secretary for the society Selskabet for Oslo Byes Vel, and editor of the periodical Saint Hallvard. He was the first head of the department for cultural heritage in Oslo, from 1956 to 1960. Among his publications are Selskabet for Oslo Byes Vels historie 1811–1861 from 1936, Vår Frelsers kirke from 1950, and a two-volume work on the Akershus Castle.
A bust of Berg was unveiled in Oslo Ladegård in 1972.
Norwegian Academy of Science and Letters.