Dr. Behrokh Khoshnevis of the University of Southern California (as well as many other 3D printer experts) are working towards developing large 3D printers that can build houses and other similar architectural objects. The device would work similarly to a 3D printer in which a framework would allow a “print head” consisting of a concrete extruding nozzle to span the construction platform. The photo here also shows a winch for installing traditional construction components as well.
from Contour Crafting at http://www.contourcrafting.org/