A sprawling building with annexes, the former Chastel de la Howarderie Mansion currently houses Costermans Antiques, a member of the Royal Chamber of Antiques and Art Dealers. Built around 1785 in the Classical style, the main building was extended in 1857 based on the plans of architect Félix Pauwels. The transformation of the ground floor to a salesroom, topped by a balcony which runs all along the façade, took place in 1954 based on the design of architect Léon Emmanuel Govaerts. The interior in Louis XVI style is particularly well preserved and includes a remarkable staircase with stuccoed decoration and statuary. On the first floor, the salons and adjoining rooms retain their panelling, fireplaces and ceilings and, as befits an antique dealership, overflow with beautiful antiques, paintings, furniture and decorative objects of all kinds.