This paper discusses the design of load-bearing systems for buildings with regard to their current lack of open-ended reusability. The reason for dismantling load-bearing systems today tends to be less related to material degradation than to a loss of functional fit with an evolving building program. It can therefore be expected that load-bearing components are reused in other systems, which extends their service life and avoids the manufacture of other components. Common design strategies to ensure the actual reusability of components consist in guaranteeing that the assembly is durable, versatile, modular, reversible, and adaptable. This paper (a) reviews these features, (b) illustrates by means of case studies that, without minimum threshold, they do not guarantee the repurpose of components into different, unforeseen systems, and (c) describes opportunities and challenges related to the design of more open-ended sets of load-bearing elements, i.e. sets whose element types allow for a substantially large number of diverse assemblies, in terms of floor plans, spans, loads, support layouts, connection types, architectural language, and integration with other building systems.