Based on work by Matts Myhrman and Judy Knox, and information in the book Build It With Bales. Plans drawn and edited by Owen Geiger, Geiger Research Institute of Sustainable Building, see www.BuildersWithoutBorders.org.

List of Materials/Specialty Tools
78 bales, bale needle (optional), twine, 9 pallets, 40 inches x 48 inches, flooring material, window (or plastic sheeting), door, 1- 3x5 lintel, 7- 2-inch to 4-inch x 12-ft roof poles, branches or bamboo, fabric or plastic sheeting, and tarp approximately 13-ft x 15-ft

Notes:
• Total cost: $300 - $350 USD
• Exterior dimensions: approximately 10-1/2 ft x 12 ft = 126 sf.
• Interior dimensions: approximately 7-1/2 ft x 9 ft = 68 sf.
• Plans based on two-string bales of approximately 15 inches x 18 inches x 36 inches to 38 inches.
• Stack bales on pallets, add spaces between pallets, if necessary, to match size of bales, gaps around the edges can be sealed with earth and/or stone.
• Six rows of 15-inch high bales = 90 inches interior height.
• Stack bales flat for stability (ties not showing) in a running bond course like brickwork (where each bale overlaps the joint below it).
• Extend bales about 1 inch over edge of pallets to reduce risk of moisture damage.
• Make 10 half bales from 5 full bales. One method uses a bale needle and twine to tie two new half bales before cutting the original strings.
• Other foundation options: tires filled with rammed earth, stone, or similar, if pallets are not available.
• Flooring options: plywood, boards (including wood from disassembled pallets), cardboard, new/used carpet, earth, (could add later to save on materials).
• Tie corner bales together on each course.
• Exterior pinning with branches or bamboo or similar materials is optional but does increase wall stiffness. Tie pins (one on each side of the wall) together with twine, place twine between bales as walls are stacked, space pins approximately18-inches apart (two per bale).
• Lintel over door: approximately 3-inch diameter x 5-inch long wood pole, metal pipe, or similar placed on top row of bales, preferably in appropriately deep notch cut into the bales it rests on.
• Window opening starts on the third row and extends to top of wall.
• Roof poles: seven poles 2-inch- 4-inch diameter x 12-ft long, set 24 inches apart, tied to 2 or 3 lower rows of bales to resist uplift (place twine between bales as walls are stacked or use a bale needle to feed twine through the wall).
• Place branches, bamboo, or similar about 3 inches apart perpendicular to roof poles to support straw above and create 6-inch to 12-inch overhang beyond surface of wall.
• Add flakes of straw on top of the walls between roof poles.
• Add fabric, plastic sheeting, or similar on top of roof system before adding straw ceiling insulation.
• Straw ceiling insulation: use broken bales or loose straw to create a curved mound. Full bales could be used in extremely hot or cold climates, but a curved surface is still needed to shed water. The increased weight of full bales might require a stronger roof, especially with a snow load.
• Cover the mound with a tarp fastened to the bottom of roof overhang (screws and washers work well).
• Door options: old doors, blankets, woven mats, recycled carpet, hides, or similar (door frame is optional).
• Window options: old windows, plastic sheeting, broken glass set in earth, or similar (window is optional, but valuable for daylight and, perhaps, cross-ventilation).
• Extra bales can be used as steps to reach the upper rows and roof during construction.
• This shelter can be easily upgraded to a permanent shelter by adding plaster, a more durable roof, and other improvements.
• This shelter should be modified to meet local needs, e.g., increase the roof overhang in rainy climates.
• Please refer to the how-to straw-bale construction guide book, Build it With Bales, by Matts Myhrman and S.O. MacDonald for detailed information on building with bales.

Owen Geiger, Ph.D., in Social and Economic Development, is the former Director of Builders Without Borders and current member of the BWB Steering Committee. An author, engineer and licensed contractor specializing in straw-bale construction and other types of sustainable building, he co-authored the Builders Without Borders Straw-Bale Construction Guides and contributed to Building Without Borders.