Low-Cost Housing Construction Techniques

Don’t confuse modular homes with old style mobile homes. Modular homes are built in sections in a factory, trucked to the home site, and assembled on a permanent foundation. This assembly line style of construction involves lower labor costs. Assembling the home on site takes only a week or two. After assembly, they resemble site-built homes. The University of Illinois at Urbana-Champaign estimates that modular homes, also known as manufactured homes, cost one-half to one-third less than similar size site-built homes.

In straw bale construction, bales of cheap straw are covered on the outside with stucco and on the inside with plaster to form the exterior walls of a home. The straw takes the place of stud walls, sheathing and insulation, and provides R-50 insulation. Straw is cheap. The U.S. Department of Energy estimates the cost of enough straw to build the walls for a 2,000-square-foot house costs about $1,000. Many straw-bale home builders do the work themselves, which further reduces building costs.

Several companies have developed lightweight spray-on concrete which can be sprayed on plastic foam forms to construct lightweight but durable walls. This construction technique has primarily been used in Third World countries to replace shacks and tents people would otherwise live in, but the technique holds promise for construction in the United States. As with straw bales, the concrete-covered plastic foam eliminates the need for wood studs, insulation and external sheathing. The material also provides excellent insulation and the walls can be assembled quickly, reducing labor costs. The cost of a spray concrete home will vary with size and location, but in India laborers were able to complete an 800-square-foot home using a product called Grancrete for about $10,000.

While inexpensive materials can lower the cost of building a home, your total costs will include many other things that can raise the price significantly. If you’re building in a remote location, bringing water and electricity to the site can cost tens of thousands of dollars or more. You may need building permits and engineering work to level the site and add a septic system. The interior finishing of the home also contributes significantly to the final cost – the flooring, walls, appliances and fixtures you choose can add up if you have expensive tastes.