While concrete is hailed as a symbol of modernity, it's a wolf in sheep's clothing for Nepal's remote mountains-expensive, environmentally unsuited and culturally tone-deaf
In the years since the devastating Gorkha Earthquake of 2015, the hilly regions of Nepal have grappled with a profound architectural identity crisis. And also, it has raised a deeper question: can we rebuild resilience without losing tradition? Once picturesque stone homes that clung to the hillsides in perfect harmony with the terrain now lie in ruins, replaced by shelters wrapped in CGI sheets or painted with concrete masquerading as progress. While concrete is hailed as a symbol of modernity, it's a wolf in sheep's clothing for Nepal's remote mountains-expensive, environmentally unsuited and culturally tone-deaf. Its use demands extensive transportation of cement and steel rebar-resources that come with significantly higher economic costs compared to local materials.
Additionally, skilled local homebuilding masons are often displaced, creating an unsustainable economic cycle, as concrete construction requires a completely different skill set to master. Moreover, concrete homes disrupt the delicate aesthetic and cultural fabric of mountain life. So, what could offer a better way forward? Two alternatives-rammed earth and gabions-have emerged as potential saviours, each offering distinct advantages tailored to the unique challenges of the mountains.
Mountain buildings are a masterclass in utilising the resources provided by the land. They were works of art and craft built by skilled hands, shaped by the land and its rhythms. The foundations are usually built with stone masonry using local materials, which are abundant in the region. The walls, constructed with stone masonry and mud mortar, are 18 to 24 inches thick, providing essential insulation against the region's harsh weather. The floors are crafted with timber, featuring thick layers of mud that create a natural, breathable surface, perfectly complementing the structural timber joists beneath. While roofs were traditionally made of wooden slates, they now largely feature corrugated galvanised iron (CGI) sheets. The carved wooden windows, doors and eave boards showcase the soul of this architectural style.
Gabions, wire cages filled with stones, are commonly used for retaining walls but can also be adapted for masonry wall construction. These wire meshes provide sufficient resistance to lateral forces, such as those caused by earthquakes. Their brilliance lies in simplicity. Gabion-based construction offers significant advantages for mountainous areas for several reasons. First, gabions enhance rather than replace local knowledge, requiring only minimal adjustments to traditional masonry practices. The only foreign material involved is the wire mesh, making it easy for local masons to adopt and implement. This scalability allows for the rapid construction of homes without disrupting familiar building techniques.
Second, gabion construction preserves the design and aesthetic of traditional homes. Third, gabions require minimal technical expertise, making them highly accessible to communities. Moreover, their cost is comparable to traditional home-building methods. Finally, mountainous regions are rich in stone, but their soil may lack sufficient binding properties for effective mortar. Gabions address this challenge by using abundant stone resources efficiently. In short, gabions strike the perfect balance: durable, affordable and culturally authentic.
Rammed earth is a traditional construction technique where layers of soil are compacted to form building components. The key to this approach lies in using the right quality of soil, which can often be found in valleys and plains within mountainous regions. However, this method typically requires the addition of cement as a binding agent, making it more expensive compared to gabion homes. One of the standout features of rammed earth buildings is their excellent thermal comfort, a crucial advantage in areas where mechanical heating and cooling are rare. The use of stabilisers such as lime or cement, combined with reinforced frames, can significantly enhance the structural integrity of these homes. And, here's the catch: with proper engineering, rammed earth structures can perform well even in seismic zones. However, the technique is heavily reliant on the availability of suitable soil, and not all areas in hilly regions possess the required type. Another challenge lies in the construction process, which demands skilled labour and meticulous attention to material preparation-resources that are often scarce in rural Nepal. Furthermore, determining soil properties and assessing the performance of rammed earth homes may require laboratory testing, as soil conditions in mountainous areas vary widely.
The choice is not just about the materials, which are, again, locality driven. It is about being mindful of the homebuilder's requirements and the suitability of the materials to the available labour and resources in the region. Both approaches have their pros and cons but are solid options from a sustainability perspective. Both rammed earth and gabions provide a way to preserve the character of mountain life while addressing the demands of safety and sustainability. The answer may not lie in choosing one over the other but in embracing a mosaic of solutions tailored to the specific needs of each community. Perhaps, the next generation of mountain homes will blend these approaches, creating buildings as enduring as the peaks they overlook. Gabions and rammed earth aren't just materials-they're opportunities to rebuild identity, resilience and pride.
Paneru, a building scientist, engineer and policy enthusiast, is a research fellow at Department of Architectural Engineering, Penn State University, USA, while Ghimire, an expert in Artificial Intelligence is a Ph.D. candidate at the University of Nebraska Lincoln, USA.
