Rediscovering the benefits of rammed earth wall systems

Rammed earth construction is one of the world’s oldest building techniques, yet many in the modern construction industry remain unfamiliar with its value. However, with roots dating back thousands of years, this ancient wall system is once again gaining attention for its remarkable sustainability, thermal performance and natural beauty. But if rammed earth is so beneficial, why is it yet to go mainstream again?

Used for centuries across Asia, North Africa and Europe, rammed earth has stood the test of time. Sections of the Great Wall of China, Moroccan kasbahs and French farmhouses were all built using compacted earth. The technique is relatively simple - moist subsoil, often mixed with gravel, clay and occasionally lime or cement, is poured into formwork and compacted in layers. Once hardened, it forms thick, stone-like walls that offer strength, insulation and durability.

The rise of industrial construction and mass-produced materials like concrete and brick eventually pushed rammed earth into obscurity. Yet, its underlying strengths never disappeared, which is why rammed earth is once again becoming more appealing in today’s eco-conscious building climate.

The material is particularly low in embodied carbon, because no firing or energy-intensive processing is used - and it often uses local materials. It is mostly recyclable with the ability to return to the earth with minimal waste. Its density helps regulate interior temperatures passively and it contains no synthetic chemicals or VOCs.

Architects value rammed earth for its natural, stratified texture that visually connects a building to its environment. Its tactile, earthen surfaces exude calm and permanence. As climate change and material shortages reshape construction priorities, rammed earth also fits the bill for regional, low-impact solutions. Without doubt - the growing demand for sustainable architecture has put this ancient technique back in the spotlight.

Modern applications

As a result, a growing number of architects and engineers are reviving and adapting rammed earth for modern needs. Glenn Murcutt in Australia has championed earth-based walls in eco-sensitive homes; Anupama Kundoo integrates earth with experimental materials in climate-resilient Indian housing and Rick Joy Architects in Arizona has used rammed earth to stunning effect in desert homes. The Salk Institute's Visitor Centre in California also features cement-stabilised rammed earth walls.

Innovations such as pre-fabricated rammed earth panels, improved mechanical compactors and even 3D printing are making the technique more efficient and scalable. However, despite its clear advantages, rammed earth faces several challenges.

Manual compaction is slow and skilled labour is scarce. Even with machinery, setup and curing times can be longer than modern alternatives. And while the raw materials are cheap, the labour, formwork and time involved can increase project costs. However, life-cycle savings on energy and maintenance often offset these expenses.

Understandably, many regions lack codes for rammed earth, complicating permits and inspections. It’s often viewed as an "experimental" method. Without proper detailing, rammed earth can also be susceptible to water damage. Techniques like wide eaves, water-resistant coatings and raised foundations are necessary. In addition, while rammed earth is ideal for low-rise buildings, it does not scale easily to high-density urban developments.

However, as the construction industry aims for net-zero emissions, rammed earth’s minimal carbon footprint and use of local materials offer a powerful solution, especially in arid or high temperate climates. It also aligns with circular economy principles and biophilic design trends. As a result, hybrid systems combining rammed earth with steel or timber framing, modern insulation, or even low-carbon concrete are emerging to address its limitations while preserving its benefits.

What needs to happen next

While rammed earth ticks all the boxes, we are unlikely to see a huge rise in this type of building due to skilled labour shortages. Updating building codes to recognise rammed earth construction, is also needed to ease regulatory friction.

Advancements in prefabrication, waterproofing and automation can bring costs down and scale up adoption, but this will take time. We also need to see a trend towards blending rammed earth with contemporary aesthetics and hybrid systems to make it more palatable to developers and clients alike.

Solve these problems and we could see a rise in more affordable and sustainable homes, especially where materials can be sourced locally. This could be a boon for desert architecture where the thermal mass of rammed earth provides temperature control with minimal HVAC needs. With proper reinforcement, rammed earth also performs well in seismic and fire-prone areas.

So, we can see, that rammed earth is more than a nostalgic curiosity, it's a potential game-changer for low-impact building. As we look to decarbonise construction and rediscover climate-resilient techniques, there’s wisdom in revisiting materials like this and the building methods of the past.

While not suitable for every project, rammed earth can be a compelling solution for those seeking sustainability, beauty and permanence. With the right support and innovation, this ancient method might just find its place in the future of modern architecture.