Earthbag / Superadobe — FarmPal

Polypropylene bags filled with earth, stacked in courses with barbed wire between layers for tensile strength. Developed by architect Nader Khalili for NASA lunar habitat research, now used worldwide for disaster relief and permanent homes.

History

Created by Iranian-American architect Nader Khalili at CalEarth in the 1980s. Originally designed for lunar construction. Now ICC-approved building method.

Cost/sq ft
$10-$30
Build Time
6-16 weeks
Crew Size
2-6 people
DIY Friendly
Yes ✓
Code Compliance
moderate
Thermal Mass
very-high
R-Value
R-1 to R-4 per foot (earth fill); R-20+ with insulation fill
Lifespan
100+ years with proper plaster

Best Climates

arid
semi-arid
tropical
temperate
mediterranean

Resistance Ratings (1-5)

tornado★★★★★
hurricane★★★★★
earthquake★★★★★
fire★★★★★
flood★★★☆☆
mold★★★★☆
termites★★★★★
bullets★★★★★

Materials

Polypropylene bags or tubes
On-site earth/gravel
4-point barbed wire
Cement for lower courses
Lime or earthen plaster
Rebar pins (optional)

Build Steps

  1. 1Excavate and level foundation trench (min 12" deep, below frost line)
  2. 2Fill first 2-3 courses with gravel for moisture barrier
  3. 3Fill bags with moistened earth (10-30% clay ideal)
  4. 4Tamp each course thoroughly until bags are firm and flat
  5. 5Lay 2 strands of 4-point barbed wire between every course
  6. 6Stagger bag joints like brickwork for structural integrity
  7. 7Create door/window openings with arch forms
  8. 8Build corbelled dome or add bond beam for conventional roof
  9. 9Apply 2-3 coats of earthen or lime plaster inside and out
  10. 10Install roof drainage system to keep water away from walls

✓ Pros

  • •Extremely low cost
  • •Uses on-site materials
  • •Disaster-resistant
  • •Beginner-friendly
  • •ICC approved
  • •Dome shapes need no wood framing

✗ Cons

  • •Labor-intensive
  • •Bags degrade if not plastered
  • •Code challenges in some areas
  • •Low R-value with earth fill alone

⚠️ Warnings

  • •Bags must be protected from UV never leave exposed
  • •Foundation must be above flood level with proper drainage
  • •Check local building codes some jurisdictions require engineered plans
  • •Barbed wire is essential it provides critical tensile strength