Arg Architects - Rammed earth wall

In a neighbourhood where more and more houses are being replaced by larger, more modern buildings, ARG architects have managed to combine history, nature and sustainability in one work. The design of the house is based on respect for the environment and the historical context of the site, with an emphasis on the reuse of materials and the minimization of construction waste. The owners of the house took the initiative to preserve what was possible and to have an environmentally friendly construction. The main parts of the house were allowed to remain in their original form, but the roof and various interior and exterior features were renovated.

One of the project's key elements is three curved interior walls. One of them is made of steel and represents fire; it curves around a fireplace in the house's central space and connects the building to the era of settlement when steel was made with fire in Iceland. The second wall is timber and separates the house's television room. The third is a so-called earth wall, created using the rammed earth method.

The artist Gísli Hrafn Magnússon had studied the rammed earth method, and when it was necessary to excavate for new pipes on the site, a material was created for the project. Instead of removing the excavated soil, it was transported a few meters into the house and used there. The method of making the earth wall has been used for thousands of years in architecture worldwide. The original idea is to utilize the soil on which the building stands, thus minimising the need to transport building materials. The method involves compressing moist soil in layers within moulds until the material becomes dense and its load-bearing capacity increases. When the wall dries, it becomes hard and durable, similar to concrete, but without requiring energy-intensive production processes. Earth walls have high compressive strength but less resistance to shear and tensile loads.

The preparation process for the installation of the wall was long. Samples were taken with the soil from the garden and submitted to Tæknisetur for testing. The material used in the earth wall must be the right mix of sand, clay and moisture. It is difficult to determine the exact proportions, as the soil varies depending on the location. Therefore, special knowledge is needed to assess the material's texture before placing it in the moulds. The Tæknisetur's test methods are designed for concrete and were not entirely suitable for rammed earth wall tests. It then became clear that it would be better if the moulds were larger and that offering more testing methods in Iceland is necessary.

Rammed earth walls are not only environmentally friendly but also practical. They store heat during the day and release it back into the space when it cools down, improving the building's energy efficiency. In addition, they are dust—and toxic-free, well suited for moisture control, and provide good sound insulation. They contribute to less material transport and reduce the building's carbon footprint.

Biodiversity

The house's roof was in poor condition, and a large part had to be removed. During the construction work on the roof, a habitat for bees and birds was discovered. Bumblebee and wasp colonies, as well as nests of woodpeckers and ladybirds, were found there. This led to a decision, made in consultation with an ornithologist, to extend the roof support beam in the sleeping wing of the house and finish the roof canopy so that it maintains and supports the area's biodiversity.

Other

The soil excavated during the pipeline construction and not used in the earth wall was used to shape the walls and embankments on the site. The garden is left wild and uncut, which further supports biodiversity.

More circular solutions were used in the renovation of the house. Paving stones from the house's site were reused in the seating area around the fireplace. These are good examples of targeted reuse of building materials.

Information about rammed earth: https://rammedearthconsulting.com/