[6] It was designed in the neoclassical style, built in red sandstone with a cement render finish and was completed in 1724.

[9] The design involved a symmetrical main frontage of nine bays facing onto the central square (now Place d'Armes).

The central bay, which was slightly projected forward, featured a segmental headed doorway framed by two pairs of Doric order columns supporting a balustraded balcony; there was a French door on the first floor.

[11] In the winter of 1870, during the siege of Belfort, part of the Franco-Prussian War, many buildings were damaged by the attacking Prussian forces, but the town hall survived.

[14] In November 2024, the council announced that the annex would be refurbished at a cost of €2.5 million to a design by LAO Architectes.