Innovation and exploration will be a major concern in these new cities and the future will generate newer materials and methods, which will result in vastly different expressions of structure, form, and function, each consistent with an evolving and changing world. The future technologies used in the construction of these new advanced cities are based on extrapolations and projections of feasible technologies and can be developed today. These newer materials will probably serve multiple purposes. They could be lightweight, high strength, and low maintenance, with acoustical properties not found in today's structures. Some new structural materials may be of a sandwich-type construction that is semi-flexible, with an inner foam core and a glazed ceramic, outer surface to allow for expansion and contraction without fracture. This will require no maintenance. Their thin shell construction can be mass-produced in a matter of hours. With this type of construction, there would be minimal damage from earthquakes, hurricanes, termites, and fires. These newer materials could combine all of these factors as an integral part of the structural components.