From time to time we answer reader’s questions.
Josh: Do earthbag homes overheat in hot, humid climates such as Haiti? My friend toured some domes in California and they were like ovens. And how does earthbag compare to cinderblock (concrete block) homes?
Owen: Domes are exposed and vulnerable to the elements, and often have insufficient ventilation. Domes are most appropriate for desert regions that cool off at night.
I highly recommend building roofed structures in hot, rainy climates using wide roof overhangs, adequate ventilation, tall ceilings and shading from trellises, trees and other plants to prevent overheating. This can include porch roofs on the hottest side(s) facing the sun, and leaving a space between the roof and bond beam for hot air to escape. Our earthbag roundhouse here in Thailand stays nice and cool. It would be interesting to know how groups in Haiti are faring with their earthbag structures. It all depends on the design details. Obviously, corrugated metal roofing exposed to full sun all day will radiate heat like crazy, and then the high mass earthen walls will store the heat. Learn from others’ mistakes.
Earthbag is definitely better than concrete block in terms of 1. transfer of heat, 2. condensation build up, so they are more comfortable. In addition, earthbag buildings are lower cost, more earthquake resistant, etc.
Patti Stouter has written three articles about building in hot, humid climates.