He participated along with German architect Elias David Hausser and Lauritz de Thurah in the interior construction of Christiansborg Palace, with wood sculpting by Louis August le Clerc. Eigtved and de Thurah, for the most part, divided up the interior assignments. Eigtved designed the king's apartments, the main staircase, the chapel's interior, the riding grounds, and the Marble Bridge ("Marmorbroen") and its two pavilions, and gave the castle its delicate Louis XIV style. Most of Eigtved's accomplishments at Christiansborg were lost in the fire of 1794.