Earth-sheltered architecture is the practice of using soil against the walls and over the roof of a building to moderate its temperature, shield it from weather, and blend it into the landscape. It is not a fringe idea — it is one of the oldest continuous building traditions on the planet, and it was formalized into a modern discipline by American architects in the 1970s.
The umbrella term covers two broad families of design. Bermed (earth-banked) homes sit at or near grade with soil pushed up against some or all of the walls and, often, across the roof. Fully underground homes are set below grade, frequently organized around a sunken courtyard or atrium that brings daylight and ventilation into the center of the plan. Both rely on the same physics: the earth is a vast, slow thermal battery.
The design taxonomy: bermed, elevational, penetrational, atrium
The most useful classification of earth-sheltered designs comes from the research literature of the 1970s and 1980s, notably the University of Minnesota's Earth Sheltered Housing Design (1979). It distinguishes several site relationships:
- Elevational (bermed) — one facade, usually facing the sun (south in the Northern Hemisphere), is fully exposed for glazing and entry while the other three sides and the roof are earth-covered. This is the most common and most easily permitted approach.
- Penetrational — the structure is largely below grade, but window and door openings “penetrate” the earth cover on more than one side, using recessed light wells so daylight reaches multiple rooms.
- Atrium (courtyard) — a fully subterranean plan wrapped around an open central court. Every room faces inward to the sky-lit courtyard. This is the classic form seen in the ancient sunken courtyard dwellings of Henan Province, China, and it remains the highest-performing option for thermal isolation.
Thermal mass and the constant of the deep earth
The central advantage of building into the ground is thermal stability. A few feet below the surface, soil temperature stops tracking the daily weather and, deeper still, stops tracking the seasons. Below the frost line, ground temperature settles close to the mean annual air temperature of the location — roughly 50–60°F across much of the continental United States. Instead of fighting a 100°F summer afternoon or a 10°F winter night, an earth-sheltered wall is only ever exchanging heat with soil that hovers near cellar temperature.
This is passive-thermal design, not insulation in the conventional sense. Insulation slows heat flow; thermal mass stores and delays it. A massive concrete wall wrapped in earth absorbs heat slowly during the day and releases it slowly at night, flattening the interior temperature swing. Pair that mass with insulation on the outside of the wall (so the mass stays “inside” the thermal envelope) and a modest amount of south-facing glass for winter solar gain, and the annual heating and cooling load drops dramatically compared with a conventional above-grade house of the same size.
Why the frost line matters
Foundations must extend below the local frost line to avoid frost heave — that depth ranges from near zero in the Deep South to five feet or more in the northern Plains. Earth-sheltered design turns that constraint into an asset: the same depth that protects a footing also delivers the stable ground temperatures that make the house efficient.
The 1970s movement and the University of Minnesota
Earth sheltering as a self-conscious modern movement was born from the 1973 oil embargo. With energy prices spiking, architects and building scientists went looking for structures that needed almost no purchased energy to stay comfortable. The intellectual center of that effort was the Underground Space Center at the University of Minnesota, established in 1977 and led by researchers including Raymond Sterling. The center's publications — above all Earth Sheltered Housing Design: Guidelines, Examples, and References — became the field's standard reference and were widely credited with moving earth sheltering from folk practice to engineered design.
The movement produced thousands of owner-built and architect-designed homes across the American Midwest and Mountain West through the late 1970s and 1980s. Interest cooled as energy prices fell and as some early, poorly waterproofed projects developed moisture problems — a cautionary history covered in our benefits and challenges guide.
Malcolm Wells, the father of earth-sheltered architecture
No single figure is more associated with the field than Malcolm Wells (1926–2009). A New Jersey architect who began his career designing conventional commercial buildings, Wells experienced what he called a professional conversion in the 1960s and spent the rest of his life advocating for what he termed gentle architecture — buildings that give more to the environment than they take. His widely read books, including Gentle Architecture (1981) and Underground Designs (1977), argued that a building's roof should be living landscape, not shingles.
Wells designed and built earth-covered structures including his own studio in Cherry Hill, New Jersey, and later on Cape Cod, and he set out a memorable scorecard for judging a building by how well it creates habitat, stores rainwater, produces oxygen, and consumes its own waste. His influence runs through nearly every serious earth-sheltered project built since.
Real examples you can point to
- Formworks Building (Durango, Colorado) — a long-running builder of earth-sheltered homes using a steel-reinforced concrete shell that is then bermed and planted, one of the few firms to keep the 1970s approach in continuous commercial production.
- The Earthship (Taos, New Mexico) — architect Michael Reynolds' off-grid, earth-bermed homes built from rammed-earth tire walls, covered in detail in our iconic projects guide.
- Villa Vals (Switzerland) — a fully hillside-embedded house whose only visible face is a curved glazed wall, showing how far the atrium idea can be pushed architecturally.
- Peter Vetsch's Earth House Estate (Lättenstrasse, Switzerland) — a cluster of sculptural, sprayed-concrete earth houses that has been continuously occupied since the 1990s.
Ready for the engineering? Continue to Building Down for the excavation, waterproofing and structural realities, or see how the idea scales to whole cities in Underground Cities.
Sources and attribution: University of Minnesota Underground Space Center, Earth Sheltered Housing Design (1979); Malcolm Wells, Gentle Architecture (1981) and Underground Designs (1977); Formworks Building; Earthship Biotecture. Temperature figures reflect general building-science guidance and vary by climate and soil; confirm site-specific values with a local engineer.