Theory is needed to explain conflicts between the intrinsic conceptual frameworks of construction: that governing what to build? and that governing how to build? The conflicts throw up uncertainties to be addressed by the strategies of building. But theorizing about the built environment has tended to be partial, suffering from growing separation between building design, construction and use, and recently from legacy concepts inherited from modernism that result in sometimes dangerously uneven explanations. Limitations of some present theoretical approaches are explained. A hypothetical scheme, a sketch-plan for theoretical discourse, is proposed based on the human transactional basis of construction-demand, regulation, supply-broad enough to unite design, use and production, and to provide a platform for applied research. A methodological regime of instrumentalism is proposed to underpin research, encourage model-building, and ensure the usefulness of the theory for practice, without which it would not be worthwhile. The scheme of the discourse aims to provide a meeting ground for the conflicted conceptual frameworks of construction.