Living in earth-sheltered housing doesn't have to mean sharing your space with the worms. With designs that are partially below ground or completely above ground, earth-sheltered housing is adaptable and takes advantage of the energy efficiency of the surrounding soil and plant life. Architect Malcolm Wells advocated and promoted the earth-sheltered architecture until his death in December 2009 [source: Weber]. He designed multiple underground homes, stadiums, airports and even bridges, and though many never came to fruition, they did forever influence the green movement [source: Weber].
One earth-sheltered design that has taken hold today is the bermed home. It is built at ground level or dug into the hillside and has earth compacted around two sides, the top/roof and along the rear. Homes like these have sub-ground living areas with central atriums or large courtyards that provide natural light, cool air and insulation.
According to the U.S. Department of Energy, elevational bermed homes, usually those situated partly in the ground with a south-facing wall open to sunshine and heat, may be the most affordable options in earth-sheltered housing. They're easier to construct and often are built into hillsides, taking advantage of natural surroundings. Underground earth-rammed homes may be more costly, but they're not covered with as much earth as you might think -- typically less than 3 feet (0.9 meters). Using more than 3 feet doesn't increase energy efficiency [source: U.S. Department of Energy].