Earthbags

Earthbags are a form of earth-filled bag construction used to build walls and structures. The system typically uses long bags made of polypropylene or other durable fibers that are filled with soils, gravel, or other stable fill. The filled bags are laid in courses, tamped to shape, and often staggered like masonry. Between courses, barbed wire or similar reinforcement is placed to improve shear strength and prevent sliding. Walls are commonly built in coils or straight stretches and may be formed into arches or domes for roofs. Exterior and interior finishes usually involve plaster or stucco to protect against moisture and weathering. Roofs are supported by a ring beam, with additional framing or structural elements as needed.

History and development: The earthbag concept evolved from bag masonry practices and gained broad attention in the late 20th century. It was popularized by architect Nader Khalili in promoting a system known as Superadobe, which helped spread the method under the broader term earthbag construction. Since then, the approach has been used in various regions for housing, classrooms, and relief shelters.

Advantages and limitations: Earthbag construction uses locally available soil, can be low cost, and offers good thermal mass and potential earthquake resilience due to its flexible, layered walls. It is relatively simple to repair and modify. Limitations include labor intensity, significant weight, and moisture sensitivity if not properly protected with plaster, drainage, and appropriate coatings. Building-code acceptance and long-term durability depend on proper detailing and local conditions.

Applications: The method is used worldwide for sustainable homes, emergency shelters, and community buildings, especially in areas with limited access to conventional construction materials.