He debuted as an author in 1959 with his self-illustrated children's book Byen som laget brannbil (The city that made a firetruck).
He released his first record album in 1974, and this was a product of many years of collaboration with the famous Norwegian folk singer and lyricist Alf Cranner.
In 1981, he started a comprehensive cooperation with another famous Norwegian folk singer and lyricist Lars Martin Myhre, that would later have a profound impact in the musical life of Norway.
Børretzen's play Synd og skam (Pity and shame) was shown on Teater Ibsen in 1994, his manuscripts always written by hand are sharp witty and always with an edge into current issues or universal everyday life.
They received a strong reaction to the so-called pensioner sketches, and therefore Børretzen decided to stop performing them due to bad conscience.