Despite its rather one-dimensional image of a multi-capital city and its small size, Brussels has a high concentration of knowledge actors. The large number of higher education institutions (HEIs) and their knowledge workers thereby hold a large potential for the city-region and its complex societal challenges. Philosophical, institutional, linguistic and disciplinary cleavages structure and influence the functioning of the system, though. They constitute the very raison d’être of collaborative organisations such as the Brussels Studies Institute (BSI), willing to transcend the many walls and (internal and external) thresholds the system implies. This contribution features the modus operandi of the institute as well as some of the tools and instruments that were developed to break down the aforementioned walls.