The construction sector is one of the most resource-intensive industries globally, contributing significantly to environmental degradation and greenhouse gas emissions. Transitioning towards a circular economy within the built environment offers a promising solution by emphasizing the reuse of building materials. This paper explores the potential of data-driven design methodologies to facilitate the integration of reclaimed materials into new architectural projects. A structured design tool is developed to assess the reuse potential of building materials, incorporating factors such as material quality, disassembly index and lifecycle performance. Through a case study involving materials sourced from the Megastores shopping mall in The Hague, the research demonstrates how data-driven approaches can a guide for deposition decisions of building materials for new circular buildings. Case studies of successful architectural projects like Biopartner 5, K.118, and Resource Rows give insights into design implementation with reclaimed building materials. This study highlights the critical need for architects to adopt innovative design tools and practices to meet sustainability targets while leveraging the untapped value of donor building.