For all of the history, design and construction of building have relied on drawings for representing the work to be done. They were defined as contracts - legal documents, were assessed by building codes, and used to manage the facility afterward. But there are two strategic limitations of drawings: (1) they require multiple views to depict a 3D object in adequate detail for construction, making them highly redundant and thus open to errors; (2) they are stored as lines, arcs and text annotations that is only interpretable by some people; they cannot be interpreted by computers.