He was born in Eidanger as a son of Lieutenant Colonel Cornelius Mathias Schilbred (1878–1949) and Marie Henriette Petersen (1885–1965).
While studying he was an editor of the politically conservative periodical Minerva, and in 1928 a member of the board of the Norwegian Students' Society.
[2] Schilbred spent his entire professional career as a teacher and headmaster in Oslo.
In his spare time he had a considerable production of genealogical and local-historical works.
He had formerly edited Tidsskrift for handelsutdannelse from 1948 to 1953, and also contributed to Aschehougs konversasjonsleksikon and Store norske leksikon.