Brussels, Jun 10 (EFE).- The European Union wants to build more housing while ensuring it remains affordable and sustainable. However, it is also aware that cement, the bloc’s most widely used construction material, is highly polluting. As a result, alternatives are emerging, ranging from low-carbon “eco-cements” to replacing cement altogether with mud and earth.
Speaking on Wednesday at a session on how Europe can move towards a climate-neutral, circular and competitive construction model, held as part of the New European Bauhaus Festival in Brussels, German architect Anna Heringer presented a proposal based on mud and rammed earth construction.
The technique, she explained, has been “proven over thousands of years, is present on every continent and in almost all climate zones, and is used in billions of homes.”
It is one of the proposals aimed at addressing the environmental footprint of the concrete industry, which produces around 5% of global CO₂ emissions, due to the calcination process used to produce cement.
“Cement, steel, and bricks require firing. Oil takes millions of years to form. Using earth in its natural state, without adding anything to it, is the most environmentally friendly and lowest-impact way to build,” Heringer said, arguing that earth should no longer be treated as “waste” but valued for being a 100% natural and recyclable material.
“Scaling it up to billions of homes”
The architect highlighted the accessibility of these materials across all regions, “including the Global South,” citing the recent use of the technique in the building she designed on the St. Michael Campus in Upper Bavaria, Germany.
“That it can be scaled to billions of homes has already been demonstrated over thousands of years,” she said.
Heringer explained that rammed earth can provide sufficient structural stability for multi-storey buildings and argued that the concept has already proven its effectiveness. A similar idea earned Austrian architect Martin Rauch the first New European Bauhaus Prize in 2021 for his prefabricated raw-earth construction elements.
However, she maintained that the approach “is not aligned with our construction industry, nor with regulations and standards that are often influenced by that industry,” even though it is consistent with “intuition and common sense.”
The architect also stressed that under the current model “it is cheaper to ship materials from China than to hire local craftsmen to build a house,” which she described as unhealthy for both society and the environment.
The local perspective and eco-cement
Carmen Díaz, Chief People and Sustainability Officer at building materials company Holcim, agreed with Heringer that the industry must move towards a more “local approach” and develop skills “within local communities.”
From that perspective, Díaz referred to the successful implementation of low-carbon cement and ready-mix concrete solutions that are also “accessible to all markets.”
“In addition, we are focusing heavily on how to build more efficiently, how to build with less material, and with local materials, so that construction is more practical and less energy-intensive,” she added.
The use of materials and the efficient management of natural resources were among the main topics discussed on Wednesday morning at the New European Bauhaus Festival, which is being held this week in Brussels and is showcasing European projects focused on community-based and sustainable architectural design. EFE
By Ignacio Blanco