True, though you still need to transport all those panels to the site and assemble them - one interesting aspect here is that the materials are (mostly) present

True, though you still need to transport all those panels to the site and assemble them - one interesting aspect here is that the materials are (mostly) present. That doesn't make for much savings of emissions for a single house, but if you built ten at once... I also wonder if you couldn't carve out a basement/cellar and use the dirt displaced to build the house over it, that'd provide storage.