[2][alpha 3] Settled in its new premises, the company soon went into decline, first as a result of the Great Depression of the 1930s, then of World War II, and finally as the piano lost its place in the furnishings of bourgeois homes.

[4] At this time, the "Pianos De Heug" sign was replaced by "Dolisy", the name of a customs agency, the new occupant of the ground floor.

[5] In 1985, the building was damaged by an attack by Communist Combatant Cells on a branch of the Manufacturers Hanover Corporation, a financial institution then located on the first floor.

[6] The building was listed in 1995 as Wallonia's immovable cultural heritage, and it underwent restoration work at the end of 2002 on the skylight roof of the facade, which had been damaged in a storm.

[7] The owners, notified by the Institut du Patrimoine Walloon in 2006, agreed to restore the façade.

[8][alpha 4] The building was purchased in early 2010 by the limited company Saint-Lambert Promotion/Iret Development as part of a project to create a shopping center called "Rive gauche".

The De Heug building was initially intended to become a hostel,[9][alpha 5] but was eventually dedicated to hosting offices.

The original technique was reproduced to replace the interior concrete slabs, which had been eaten away by humidity.

This glass and steel column, both aesthetic and functional, emphasized the vertical aspect of the quayside.

[17] According to Anne-Catherie Bioul and Chantal Mengeot, the building is reminiscent of the industrial aesthetics advocated by the Bauhaus movement, characterized by simplicity and rationality.