Papercrete is re-pulped paper fiber with portland cement, clay and/or other dirt added. The portland cement sounds like it would not be green building, but with such a small amount it offers a reasonable tradeoff. Adding mineral materials like sand and adobe minimizes curing shrinkage and creates a more durable fireproof product although less insulative and weightier.
As an approved building material, papercrete has not been around long enough or people have not found it economically feasible to use enough to have been tested. In the U.S., most building materials are standardized through engineered tests and accepted by code approval agencies, but that takes time and money. If an engineer will sign off on an alternative material or building techniques, usually an inspector will consider them an acceptable practice.
View the list for the attributes of papercrete building and for links to videos made by Kelly Hart, the papercrete guru. The picture is of the Hart papercrete-finished home. See the articles below for more information on earthships closest to Greenville, South Carolina and getting earthship homes approved in the area.