Adobe Construction - A dun-dried, unburned brick of clay mixed with straw. Adobe walls are thick and a good thermal mass although it a poor insulation.
Cast Earth - Concrete like composite with soil as its bulk component and set with gypsum. Invented and patented by Harris Lowenhaupt.
Cob Construction - Similar to adobe, mud and straw mix, but not in bricks instead a sculpture. A little better insulation over adobe and more versatile in building styles.
Conventional - You can build a conventional home but still use as many earth friendly (and human friendly) objects as possible. No Voc paints, passive solar, solar panels
Cordwood Construction - Wood 12 to 24 inches thick stuck together with mortar. Cordwood construction can be sustainable depending on the design and process. The wood acts as the insulation and the mortar is the thermal mass.
Earthbag or Sandbag - Basically the same theory as sandbags used in floods. Bags are stacked like a bunker. The most common bags are made of woven polypropylene and filled with rock, dirt or any inorganic material. Walls are covered with opaque material, stucco or plaster. A very inexpensive solution for earth building.
Earthship's - Earth sheltered autonomous buildings. Made by recycling automobile and ramming earth in them. Rammed earth is taking clay or sand and packing it into the tires(and other objects). Earthship's are made from a lot of recycled material often including beverage bottles and cans for non-load bearing walls. In the 1970's Mike Reynolds invented these homes. There is a whole community of Earthship's and a couple here in Flagstaff.
Grey Water - The re-use of sink and bathtub water to water plants and indoor or outdoor gardens, trees or lawns.
Straw bale Homes - Straw and grass bales used as load-bearing walls or in post-and-beam construction. Bales are stacked like bricks and covered with plaster or stucco. The straw bales are great insulation.
Stone - Any type of rock is used throughout. Great thermal mass in the stone but poor insulation.