Imagine building permanent houses anywhere in the world with whatever is on the site. Not the building materials common to the area, but the material actually on the site – namely the terra firma. The sand; the clay; the dirt. That has been the dream of Iranian- born California architect Nader Khalili and the mission of the Geltaftan Foundation, an organization Khalili founded to study and promote fired-earth structures. Bothered by the cost of housing, both to the planet and to poor Third World countries, Khalili has spent the past 12 years developing a method of making permanent structures anywhere from the most common substance on the Earth, which is of course the earth itself. The idea was sparked by a