The concentration of population in urban centers and mega-metropolises makes it necessary to rethink appropriate real estate schemes to meet the needs and aspirations of citizens, boost the economy and promote the sustainability of these urban concentrations. Vertical formats seem to have reached management limits that force to rethink densities and mixes of uses much more complex than those proposed in traditional urban planning. We will analyze the role of investment in the reconversion of existing cities and new global projects.