The issues and challenges involved in controlling the collaborative changes in a Building Information Modeling (BIM) data repository, in a multi-model collaboration environment, are discussed. It is suggested that managing iterative changes in BIMs is a database problem, exacerbated by the long transaction times needed to support collaborative design progression. This is yet to be resolved in the construction industry and better solutions are needed to support the underlying workflows and computing operations for seamless collaboration on BIMs. With this in mind, this paper proposes the use of the structural and semantic characteristics of BIM objects as a mechanism for tracking changes across co-developed solutions. The creation of object signatures, using hash codes derived from their characteristics, provides a potential mechanism for object comparison and effective change recognition and management.