How an ancient technique became the material of the moment for architects seeking to build with the land rather than on it.
Rammed earth—pisé de terre in French, tapial in Spanish—is among the oldest construction techniques in the world. Sections of the Great Wall are rammed earth. The old city of Shibam in Yemen, its tower houses rising nine storeys from the desert floor, is rammed earth. The technique is so old that it predates the concept of architecture as a profession.
For most of the twentieth century, it was considered a material for the developing world, or for the distant past. In the Western architectural imagination, concrete had superseded it utterly—concrete was modern, rational, controllable. Rammed earth was vernacular, approximate, pre-industrial.
What has changed, in the last decade, is the growing awareness that concrete is among the most carbon-intensive materials humans produce. The cement industry alone is responsible for approximately 8% of global CO₂ emissions. Against this background, a material that is literally the earth beneath your feet—that can be sourced, in many cases, from the excavations for the building's own foundations—looks rather different.
But sustainability alone does not explain the renewed interest. Rammed earth has aesthetic qualities that no other material replicates. Its surface records the process of its making: the horizontal strata of successive compacted layers, each a slightly different colour depending on the mineral composition of the soil at that depth. A rammed earth wall is, in the most literal sense, a cross-section of the site. It carries geological time in its face.
At Vale House in Portugal, we used soil excavated from the building platform mixed with local limestone aggregate. The resulting walls have a warmth and specificity that no imported material could have achieved—a wall that could only have been built there, from that ground, in that light.
Written by
Forma Studio
