Rehabbing old houses is a traditional way of providing low-income housing. By redesigning the exterior, you can transform a dilapidated house into an attractive home but still maintain affordability. The interior can be rehabbed as well, with new wall and window treatments. If time and money allow, redesign the placement of partition walls for more efficient use of space. Take some pictures of old houses and redesign the exterior and interior, using your own ideas. Read accounts of other projects, such as architectural designer Nancy Fishelson's transformation of an old farmhouse by exterior improvements, found at countryliving.com. View before-and-after photos of renovation projects, such as those found on Pride Home Improvements at renovatewithpride.com, to help give you some ideas to work with. Even projects that aren't specifically for low-income housing can provide ideas you can modify for your needs.
A new trend is to use prefabricated building blocks, then assemble them on-site. According to an article in The Architect's Newspaper, time constraints are the chief complaint by architects when dealing with low-income housing. California architect Michael Maltzan overcame this issue by designing a low-income apartment complex with prefabbed building blocks, which reduce construction time significantly while still maintaining quality.
Mark Fuller writes on bobvila.com about a contractor in South Charleston, S.C., who welded together four 40-foot-by-8-foot-by-8-foot used shipping containers to form a house. Another use of nontraditional materials involves welding together silos and silo domes for a multistory igloo-like house.