Friday, November 11, 2005

Earthbag Foundations

Earthbag foundations offer many advantages over reinforced concrete foundations and work well with many types of sustainable buildings. In particular, they are low-cost, fast and easy to build, require no cement (a major cause of global warming), and require no forms or expensive equipment.

Earthbags are simply polypropylene sandbags (or rice bags) filled with soil, sand or aggregate obtained from or near the building site. Unlike adobe or rammed earth, which require a rather specific mix, almost any type of soil or aggregate will work (expansive clay soils are not recommended for foundations). Aggregates are preferred for foundations because they will readily drain away any moisture and prevent wicking into the wall system.

Designed to control flooding and resist explosives, earthbags are amazingly strong, durable and versatile as long as they are protected from direct sunlight. Keep earthbags tarped until they are plastered.

Some typical uses include:
1. earthbags on a rubble trench foundation in mild climates (to raise wall system above grade)
2. aggregate-filled earthbags starting below grade and extending well above grade in flood-prone areas (reduces risk of the structure being undermined – example: a rubble trench could get scoured away and soil-filled bags on lower courses could dissolve)
3. earthbags filled with scoria (lightweight volcanic aggregate) in cold climates (example: scoria-filled bags are equivalent to a frost-protected foundation, and therefore eliminate the need for rigid foam insulation and extensive excavation)
4. scoria-filled bags in desert regions or tropical climates as a cooling strategy

For more information:
Earthbag building information at

Saturday, November 05, 2005

Emergency Shelter for Pakistan

The death toll mounts as winter closes in on the survivors of the recent earthquake in Pakistan. Emergency shelter is essential for the survival of up to 3 million - and time is of the utmost importance.

The Geiger Research Institute of Sustainable Building, along with Kelly Hart of, is finalizing an emergency shelter design that could save many thousands of lives and alleviate considerable suffering.

The challenge is to provide quick, safe, decent shelter with minimal tools and supplies to sustain life through the winter. Access to remote areas is extremely difficult, since many roads have been destroyed or blocked by landslides. Because of these and other difficulties, and the fact that winter will soon create a much more dire situation, fast easy-to-build temporary shelter (that can be upgraded to permanent housing later) seems most appropriate.

The proposed design incorporates a round, earthbag structure partially inset into the ground. Rice bags or sandbags are filled with soil from the building site and tamped in place to create the walls. The roof is built with poles salvaged from destroyed buildings, covered with straw, grass, leaves or whatever is available, covered with plastic sheeting or tarps, and bermed with earth to hold in place. The size can be adapted to meet to site-specific needs.

A typical shelter could be built in 90 hours, not including plastering. For example, this structure could be constructed by 5 unskilled workers working 6 hours a day for 3 days.

Free plans and specifications are posted at:
Emergency Shelter Plans for Pakistan

Earthbag Dome Building (another option for earthquake zones)

More earthbag building information at