This is a very interesting book. It's mostly not about natural building, but rather a book about alternative wall building. Of the four major parts of a house - foundation, floors, walls, roof - this is an awful lot of information about walls, and very little else. Foundations covered in a few cursory pages, almost nothing on roofs, and nothing on floors at all, except for ground level earthen floors. There is less world-saving going on than meets the eye. Almost all the bad stuff whether large amounts of timber, or reviled composites is in the roofs, floors, and foundations. When it comes to having wildflowers as part of the roof, they even embrace some pretty nasty membrane products. There is also a fair amount of self-delusion going on. In the section on timber frames the author mentions the savings to be had by timber framed walls vs. stud walls, but makes no mention of the unsustainable old growth used in timber frames. Nor does he mention that the infill to timber frames is either the same studwalls he claimed to avoid using, or highly toxic SIPs. in total most timber buildings are built twice once for the frame, and enough infill material to again carry all structural loads. The same comments can be made about straw bale, cordwood and so forth, often as much wood is used avoiding studs as using them. Natural building is completely unlikely to make an ounce of green difference in the West. It mainly won't be used, and where it is, it will just be another trophy home "look". Still it's all great stuff for dreamers, and the odd few who will actually build their own little earthship. Because of all the authors contributing, the standard of information is highly inconsistent, but in the main good. Do we really need to read after 200 pages a section on timber framing that starts from theoretical constructs like what is architecture and engineering, and works on to maters even more obscure? Nonetheless, there is solid information throughout the book.