Sund studied architectural engineering at Trondheim Technical College (Trondhjems Tekniske Læreanstalt), graduating in 1897.

[2][3][4] In collaboration with August Nielsen, the architect and head of planning in Aker Municipality, he designed a number of churches and other buildings throughout Norway during the first years of the 1900s.

Sund was also a painter and with Renée was a founding member of the London Group along with Walter Sickert, Robert Bevan, and Harold Gilman.

This included experimental work by Jacob Epstein, Wyndham Lewis, and others that shocked many that saw the exhibition, which ran from December 16, 1913 to January 14, 1914.

Sund also illustrated books; notably, Ravenna, a Study by Edward Hutton (1913) and The Charm of Venice by Alfred H. Hyatt (1908).