  The long-term usability of digital building documents is essential for the
maintenance and optimization of infrastructure portfolios. It supports the
preservation of building-specific knowledge and the cultural heritage hidden
within. However, having to do this throughout the lifecycle of a building - or
even indefinitely - remains a major challenge. This is especially true for
organizations responsible for large collections of digital building documents,
such as public administrations or archives. In this article, we first describe
the challenges and requirements associated with preservation tasks, and then
introduce the concept of so-called representation information within BIM
(Building Information Modeling). This type of information is important to give
meaning to the stored bit sequences for a particular community. Then, we design
a repository for representation information and introduce some so-called 23
BIMcore content elements. Finally, we focus on BIM and the construction sector
and explain how the proposed repository can be used to implement the two
concepts introduced in the ISO reference model OAIS (Open Archival Information
System), namely the representation information and the context information, as
well as the concept of significant properties, which has not yet been
explicitly modeled in OAIS.
