Straw bale building was one of the first types of natural homes that we began to look at. It is one of the more common types of natural construction due to its ease of building and ability to fit to code. I have not built one myself, so I don’t have any pictures and am only sharing the information I have gathered for my own use.
Why build with straw bale? One huge reason is its energy efficiency. Straw is an excellent insulator with an R value of 35-50. To compare, fiberglass walls have an r value around 12. These thick straw walls also provide good soundproofing. The fire resistance is higher than that of a standard house by about 3 times. The thick packed straw does not allow oxygen through so that it burns very slowly. Straw is normally a waste product of grains. Much of it is just burned rather than being used in some way. There is apparently enough straw wasted per year to build around 2.5 million homes! Don’t forget the obvious good qualities of straw bale such as the lack of toxic chemicals in your home.
The building of the homes seems to be fairly simple. A standard foundation is poured first. You can then choose to build a stick frame and fill in with straw bales or to use the straw bales as the actual load bearing walls. If you build a stick frame, it can cost more but you will have a much easier time finding a contractor to work with for building. If you do it yourself this won’t matter. The other reason to build a stick frame is to fit the codes. Some areas will only allow the straw to function as insulation, in which case you basically build a standard house and just fill the walls with bales. Once the bales are stacked, you cover them with an air tight adobe type material. This material is clay, sand, and shredded straw. This is a time consuming process, but allows for much creativity. You can be as artistic or plain as matches your personality. The options are endless. The roof can be built in a number of ways from a standard roof to an earthen roof or a rain collecting roof. Anything you choose to build. The house can be equipped with standard electricity and plumbing, but these can not be run through the straw bale walls themselves. And that is the quick straw bale “instructions.”
The cost of the house is of course important as well. There seems to be a huge range depending on how much you do yourself and what is readily available. They can cost the same as a standard house, but save you monthly on heating and cooling costs so you seem to make out either way. I found one site pricing a straw bale home at $88,000. The complete breakdown is available here:
www.buildingwithawareness.com/information.html. A couple other excellent websites are: http://www.strawbale.com/ and http://www.houseofstraw.com/ That last website features a house of 880 sq ft at floor level plus a sleeping loft for $50,000. Overall straw bale seems to be a pretty good option for us. Warm, safe, and not too expensive.