Hansen was among the leading architect-designers active in nineteenth-century continental Europe. He was born in Copenhagen, where he trained before leaving for Germany. In Hansen's furniture design one can appreciate the influence of his Danish training as well as anticipating the progression of Viennese design towards the turn of the century.

While trained in Copenhagen, the “Athens of the North,” Hansen quickly broadened his sphere of influence with major commissions in Athens in the 1830s and 1840s before moving permanently in 1846 to Vienna, where he became involved in designing several public buildings along the Ringstrasse, including the Houses of Parliament. He also enjoyed prestigious domestic commissions throughout his career for the haute bourgeoisie (including the bankers Ephrussi and Epstein) as well as the Austrian imperial family. He designed glass for the Lobmeyr firm, including examples shown at the Paris 1867 and Vienna 1873 World's Fairs.