Abstract The preservation of scientific and cultural heritage is increasingly linked to the maintenance of long-term availability of digital information, for which no general strategy has been developed yet. In the cultural heritage domain, a digital representation may exist as a documentary representation of an existing analogue object – however, in some cases, it may also be the only remaining documentation of an analogue object which has been destroyed or lost. In the documentation of architecture, a diversified mixture of analogue materials, like notes and sketches, as well as of “born digitals”, like CAD drawings and 3D-laserscans, is being generated. With the shift from analogue 2D plans to digital 3D representations in architecture, these materials create a growing data pool ideally documenting an object’s life cycle. Such complex time studies can be irreplaceable cultural heritage objects, as they document architectural structures over changes due to remodeling, planned demolition or unplanned destruction. In February 2013, the EU-funded project DURAARK – Durable Architectural Knowledge was launched under participation of the Leibniz University Hanover (L3S/TIB). The three-year project aims at the development of methods for the long-term preservation of architectural 3D data. From the ingest, storage and retrieval of 3D objects to measurements for the preservation of long-term availability DURAARK covers a wide range of processes and methods. The paper presents first findings of the project and covers identified requirements for the preservation of 3D data from the data storage, the file format choice as well as the semantic perspective.