Earth sheltering has three common uses: a root cellar that holds food at 2-10 °C year-round, an earth-covered roof over a living space, and a storm or fallout shelter. The principles are the same, drainage first and a roof built for the soil load, but the stakes differ, since a failed root cellar loses food and a failed shelter roof kills the people inside.
Applications are particular buildings designed around earth’s thermal stability, weight and mass.
Same Rules, Different Consequences
Three applications share the same earth-sheltering rules:
| Application | What earth provides | Special concern |
|---|---|---|
| Root cellar | Steady cool temperature, high humidity | Humidity control and ventilation; see Root Cellars |
| Earth-covered roof over living space | Insulation, fire resistance, camouflage | Roof load and waterproofing; see Earth-Covered Roof Living Spaces |
| Storm or fallout shelter | Protection from wind, debris and radiation | Ventilation, flooding, a second exit; see Storm and Fallout Shelters |
A root cellar maintains 2-10 °C year-round, which suits root vegetables, fermented foods, dairy and preserved meats; for storage design see Storage Buildings.
What You Need
- A site with a low water table and good drainage.
- A roof structure sized for the load; see Structural Considerations.
- Ventilation and an exit appropriate to the use.
Method: Match The Margin To The Stakes
Step 1: Choose the application and note who will be inside, and for how long.
Step 2: Apply the same drainage and waterproofing whatever the size.
Step 3: Raise the safety margin with the number of occupants and the length of stay.
Step 4: Plan the air for people, food or both; people need fresh air, food needs humidity control.
Common Mistakes
- Treating a shelter like a cellar. People need ventilation and a way out.
- Building small to save effort and skimping on the roof.
Safety
Digging and roofs
Any pit deeper than about 1.2 m needs sloped or shored sides, and an earth roof fails without warning. The root cellar pit in the parent article is 2-3 m deep, so the digging precautions in Cut-and-Cover Method apply in full.
What’s Next
- Learn next: Earth-Covered Roof Living Spaces
- Combine with: Storm and Fallout Shelters