its only presence in the street-front is in the form of two almost adjoining houses. The one on the right leads the visitor straight to the core of the building ==> https://www.vai.be/en/buildings/cultuurinfrastructuur/theater-le-rideau-de-bruxelles

Building 9 between the 2 building in question (now abondonned) seams to be still occupied in 2022 : https://www.mapillary.com/app/?pKey=262848092601250

Renovation was before that : https://openpermits.brussels/fr/_09/PFD/584412

So user has more information , or outline is guessed.