Background
He was born in Vik, Sømna as a son of politician Sivert Nielsen (1823–1904) and Jonethe Cornelia Falck Heide (1833–1927).
He was born in Vik, Sømna as a son of politician Sivert Nielsen (1823–1904) and Jonethe Cornelia Falck Heide (1833–1927).
From 1918 he partnered with architect Harald Sund. Among their works were Majorstuen Church, Fredrikstad Library (both finished in 1926) and the diocesal seat in Tromsø (1924). From 1920 to 1947 Nielsen was the director of regulation in Aker municipality.
He also led the work of regulating Narvik city.
He died in 1956.
He was also a member of Aker municipal council from 1919 to 1922.