The paper introduces a new approach for the representation of masonry walls in Building Information Modeling applications. The proposed representational scheme addresses the different types and levels of information required to support the design and construction of masonry walls. In particular, the paper proposes the concept of masonry wall 'region', as a suitable abstraction to represent the variety of view-dependent features that characterize the life-cycle of masonry walls. At the geometric level, a masonry region works as a surrogate for the description of arbitrary aggregation relations without the cost associated with the explicit propagation of masonry units. In this way, a higher degree of semantic expressiveness can be achieved while keeping the design model flexible and agile. The concept of masonry regions motivates the formulation of a conceptual data model as foundation upon which different masonry-specific applications can be developed in the future, along with the definition of model views necessary to support masonry related data queries and exchanges. The paper outlines the theoretical background behind the concept of masonry regions and its relationship with the Industry Foundation Classes (IFC). Finally the paper introduces a proof-of-concept implementation for a masonry wall schema, and discusses the next steps in the research.