Immersive digital reconstructions are increasingly used in cultural heritage research, yet their long-term preservation is rarely addressed as an integral part of the reconstruction process. This article addresses this gap by presenting a preservation-aware workflow that combines archival research, manual three-dimensional modeling, interactive visualization, and metadata-driven preservation. Using the digital reconstruction of Thomas Mann’s Munich residence (“Poschi”) and, in particular, its His Master’s Voice 192 gramophone as a case study, the article demonstrates how historical objects reconstructed from incomplete archival evidence can be systematically documented and preserved for long-term reuse. The proposed approach integrates the Open Archival Information System reference model with the Building Information Modeling (BIM) Core metadata model to capture both the digital assets and the production decisions underlying the reconstruction. Implementing all 23 BIM Core metadata elements demonstrates the practical applicability of this preservation strategy and provides structured representation information to support future interpretation, reuse, and migration. The study shows that integrating reconstruction and preservation from the outset improves the transparency, reproducibility, and long-term usability of immersive digital heritage environments. The proposed workflow is transferable to a broad range of digital cultural heritage projects requiring both immersive reconstruction and long-term preservation.