Infill Systems are well-organized product bundles or “kits” brought into a demised space to make it habitable for the chosen function. Infill systems by definition are not random collections of parts. Like any system, an Infill System enables a variety of individual solutions. An Infill System will, for example, yield a variety of floor plans in a given space, and, within that floor plan, will allow specific equipment and cabinet layouts to be selected from a menu. In this sense, infill systems are “open systems” in which one product (from one company) can be substituted for another (from still another company) performing the same function. Infill Systems are thus needed to make such open buildings live for a long time. This means a new industry will eventually evolve to serve the changing user level. This new industry will eventually be large and will rival the automobile industry in magnitude. Companies operating in this mode will depend on franchised dealer networks, good logistics, sophisticated information technology, multi-skilled installers, and high-quality products. This will constitute a revolution in building – a new wave on the road to a sustainable built environment.