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Rammed earth construction is a process of compressing a damp mixture of earth that has suitable proportions of sand, gravel, clay and 5-10% cement (for extra strength and durability) into an external supported frame that molds the shape of a wall section creating a solid wall of earth. After compressing the earth, the wall frames can be immediately removed for the walls to dry and harden. The structure can take up to two years to completely cure, and the more it cures the stronger the structure becomes. When the process is complete it is much like constructing a hand-made wall of solid rock.

Rammed earth has seen a revival in recent years as people seek low-impact building materials. Considered to be a naturally available product,it has a heavy thermal mass and provides a natural barrier to cold winds and forces of nature (including insects) . Rammed earth provides the ability to utilize locally available materials with little embodied energy and harmful waste. The earth used is typically subsoil, leaving topsoil readily available for agricultural uses.

Rammed earth has very high thermal mass and can be used in passive solar design. The density and thickness of rammed earth means hot or cold temperature penetration has a slow rate of thermal conductivity. Rammed earth also possesses good soundproofing and fire-resistant characteristics.

Rammed earth can carry a heavy load (approximately two-thirds of the equivalent thickness in concrete) and using re-bar reinforcement can prevent failure caused by earthquakes or heavy storms. Correctly crafted rammed earth walls will prevent potential infestation from termites and other insects. The walls require no toxic treatment with virtually no off-gassing and the material is reusable and biodegradable.

Earth buildings are durable and generally require very little maintenance as long as they are not exposed to driving rain. The material provides more air exchange than concrete structures allowing the building to breathe without significant heat loss.

Consistent workmanship is critical for both the appearance and the strength of rammed earth walls, so site work has to be of high quality - an area of wall that is not mixed or rammed correctly can ruin a whole panel.

The effects of water can cause rammed earth walls to degrade, although it may take a long time. Vertical surfaces exposed to as much as 25 inches of rain per year will erode approximately 1 inch in 20 years. Horizontal surfaces like the top of a wall, on the other hand, can erode as much as 2 to 3 inches in a single year. To provide weather protection, overhanging eaves or verandahs are needed. The New Zealand Standard for earth building specifies the size of the overhang for each part of the country.

Foundations must prevent rising damp. Modern earth buildings have conventional concrete footings, either strip or slab. A damp-proof course should be laid between the concrete and the wall to stop rising damp.

Earth walls are very heavy and only work well on stable sites with good foundations.

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