Rammed earth can be defined as a formed and compacted earth wall.

Rammed earth walls are made on site, using specialized formwork that is erected along the concrete slab or footing where the wall is designed to be situated. Earth, cement, water and waterproofing admixtures are blended to a damp consistency then compacted in layers inside the formwork. The following day the formwork is stripped to reveal the new rammed earth wall.

Rammed earth buildings are made using predominately rammed earth walls.

Most rammed earth walls have a thickness of 300mm for solid un-insulated, or 450mm for insulated.

Insulated rammed earth walls use a 50mm Styrofoam or similar that is built in the centre of the wall to create an insulated barrier to prevent temperature transfer into or out of the building.

Rammed earth buildings are increasingly popular for a few reasons. Firstly, they have a uniquely natural appeal unlike most manufactured wall building products. They are incredibly solid in appearance and give buildings a sense of grounding and honesty. Secondly, if rammed earth buildings are carefully designed, they can minimize the need for excessive heating and cooling. Design of rammed earth buildings needs to consider aspect to allow winter sun into the main living areas. Good design also needs to minimize western openings to prevent afternoon summer sun from entering. Earth Structures Group also suggests eave overhangs on the north side of buildings (in the Southern Hemisphere and south side in the Northern Hemisphere) to prevent excessive summer sun from landing into the building. Thirdly, there is a sustainable benefit from using rammed earth walls. Rammed earth uses minimal processes to build. They are site-built thus minimizing the many energy-expensive manufacturing processes of brick, concrete or steel-clad walls. When these three elements of rammed earth are considered there are many benefits from using rammed earth as a walling alternative for many buildings.

The two disadvantages of rammed earth are: Firstly, if the proposed building is difficult to access it can make the construction process slow and at times impossible to build. Small, inner-urban sites may not allow for rammed earth to be built. Rammed earth is typically better suited to larger urban, rural or commercial sites. Secondly, rammed earth suits simple, straight wall design. Complex, curving shaped rammed earth walls are slow to form and can result in added time on site and excessive expense.

The process of constructing rammed earth walls begins with materials such as road base aggregate and bagged cement being delivered to site and stockpiled in a convenient place beside the proposed building. Next, specialized formwork is erected along the concrete slab or concrete footing edge according to the building design. Rammed earth walls are built as a series of interlocking monolith panels, each panel allowing for door or window openings. Corners are built as entire sections. Panel lengths cannot exceed 4 metres between control joints to minimize the risk of shrinkage cracking. Next, the materials are blended on a mixing pad adjacent to the building, using a skid-steer loader. The materials are blended dry then water is added until it becomes a damp consistency. Next the damp, blended earth material is rammed into the formwork using pneumatic compactors driven by an air compressor. The material is compacted in layers up to a height of 600mm, then a further 600mm layer of formwork is fixed in place and the ramming process repeated until the total wall height is achieved. The formwork is stripped the following morning to reveal the new rammed earth panel. The process of building the next panel is repeated until the entire wall structure is finished. Rammed earth wall panels take between two to six days to dry depending on the ambient climate. Roof and adjacent wall structures can be fastened to the walls after a week of construction.

History suggests that rammed earth was used as one of the earliest non-nomadic walling systems, potentially in the Tigris-Euphrates plains of Persia. Rammed earth requires formwork, so it is likely that some simpler earth walling methodologies like cob of mud brick were used first. The rammed earth walls provided security against roaming wildlife and a thermally ideal shelter in hot climates. Rammed earth spread throughout The Middle East, North Africa, Central Asia, the Indus Valley and into China and was a staple building method (with mud brick or adobe construction) for millennia.

Rammed earth can last indefinitely so long as there are proper capping over wall top surfaces and so long as the base of the walls are a minimum 75mm up from the surrounding ground, to prevent rising damp. The walls are impact proof, will withstand rain damage, can be pressure washed if they are marked with mud, pen, scuffs from boots etc.

Earth Structures Group place 25mm conduits and metal wall boxes on which power points, lights switches and data points can be fastened. The plastic conduits extend to the tops of the walls and electricians can feed their cables and wires down to the boxes below after we leave.

In most cases, damage can be repaired using the same blended mix as the walls. Earth Structures Group provides clients with a maintenance manual upon completion of the wall construction. The group members can be contacted for any repair work (there is surprisingly little call for it)