The new building was designed, initially by Joseph Étienne, and later by Richard-François Bonfin, in the neoclassical style, built in ashlar stone, and was completed in 1778.

[2][3][4] The layout involved a three-storey main building at the back of a courtyard, with single-storey wings on either side and an arcaded screen at the front.

The central section of three bays, which was also slightly projected forward, featured three rounded openings on the ground floor.

[8] In the late 1870s, two new wings, intended to accommodate the Musée des Beaux-Arts de Bordeaux, were constructed behind the main building to a design by Charles Burguet.

[9] The rebuilding after the fire involved a new council chamber, completed in 1889, which was designed in a style characteristic of official architecture during the Third Republic.