Historically, “built environment” referred to all elements of the human-made physical environment, that is, it stood in contrast to the natural environment. Specific use of the term varies widely and is not altogether consistent within or across disciplines, in large measure owing to the functional division of labor that fosters divergent spheres of attention. Such differences are conceptual and applied in practice. For instance, traditionally among the engineering professions the phrase typically refers to the complex of activities, technologies, practices, and structures implicated in the generation, transmission, and delivery of energy and other utilities (e.g., water, sewerage, communication).