This chapter has touched on only the smallest sample of the natural building movement and its materials. Many of the worlds thousands of indigenous and vernacular building traditions could be included in this renaissance. Hybrid systems combining a number of the above materials are being improvised on a monthly basis. And because I have chosen to focus on wall-building systems, I have not emphasized the growing popularity of natural building products and systems for flooring, roofing, insulating, sealing, etc. That said, a question remains: especially given the eccentric fringy look of so many cob cottages, earthships, and cordwood dwellings, how big can the natural building