This paper presents two cases of material reuse in architectural practice, employing bespoke computational workflows. The first unpacks a complete cycle of from building demolition of an existing building in Järvsö, Sweden, through the design and fabrication of a temporary and mobile pavilion for use at a series of urban events, to its final destination as a wind shelter not far from the forests where the material was initially harvested. The second presents scaled approaches and methods to respond to the competition brief for the redevelopment of a partial urban block in Berlin, using the material stock from the existing building as a material library. Both cases have been developed in constrained project contexts where the resources of the material libraries have been limited and directly associated to the project - rather than being part of an open market of re-used resources - allowing data on availability, amount, and quality to be readily available. In this sense the approach can be defined as a project-confined re-use workflow, providing the opportunity to target the association between the design modelling environment and the material library.