Summary for app

Conventionally built buildings that use significant amounts of cement, bricks, and metals tend to have high embodied carbon emissions, and consume large amounts of energy to heat or cool them while they are being used. New construction techniques can help reduce both. The reinforced and stabilised rammed earth construction technique uses materials that can be sourced locally and affordably, and only has an essential, minimal amount of cement. This solution integrates modern technology with traditional practices. It has the multiple advantages of reduced carbon dioxide emissions, less energy demand, and lower electricity bills. Sustainable Future Nepal has already built over 50 such structures in Nepal over the last seven years.

The construction sector is responsible for a significant proportion of carbon dioxide and other greenhouse gas emissions worldwide and in countries of the Hindu Kush Himalaya (HKH). This has to do with the cement and other materials used in buildings, and later, the energy needed for the heating or cooling such structures when they are being used. Innovative solutions are much needed to reduce both greenhouse gas emissions and energy demand.

The problem

Conventional construction materials and practices have a huge carbon footprint as the production of cement, bricks, aluminium, and metals is highly energy-intensive and emits large volumes of carbon dioxide into the atmosphere. Even after its construction, a poorly constructed building demands a lot of energy to operate and function, making the housing industry responsible for even higher greenhouse gas emissions. Furthermore, a country like Nepal, which lies in a seismic zone, requires buildings to be resistant to earthquakes.

The solution

In order to minimise the carbon footprint of the construction industry, increase energy efficiency, and also enhance indoor comfort, we have developed a reinforced and stabilised rammed earth construction technique, the materials for which can be sourced locally and affordably in rural mountain regions of Nepal and elsewhere in the HKH. This solution enables societies to build comfortable, earthquake-resistant buildings, and helps reduce carbon emissions. Rammed earth construction also provides ‘thermal mass’ which enables greater thermal insulation, thereby keeping interiors warmer during the winter, and cool during summer.

Implementation

Earth is a common material in much vernacular architecture – which uses traditional materials, locally sourced – across the world. However, traditional earth construction is limited to small buildings, and carries the risk of failure during earthquakes. In contrast, we stabilise our earthen walls with a minimal amount of cement and strengthen them further with reinforcing steel bars, which allows the walls to be strong in tension as well as compression. This solution integrates modern technology with traditional practices and improves the structural capacity of earth construction.

Positive results

Over the last seven years, since 2015, we have built 50 buildings, including individual homes, schools, hospitals, and farmhouses using this reinforced and stabilised rammed earth construction technology. Currently, we have five ongoing building projects, and five more are in the pipeline. Most of these have the pleasant look of traditional housing and combine that with comfortable and healthy living conditions. This solution has clear environmental benefits as these structures only require a small amount of cement relative to concrete structures and unlike bricks, can be air-dried without the need for firing that brickmaking does. This reduces the emissions of greenhouse gases into the atmosphere. Additionally, the thermal properties of rammed earth reduces the use of heating and cooling systems by controlling indoor temperatures, further reducing the carbon emissions associated with a building’s operation. It also reduces the electricity bills for its residents, which are usually associated with high energy use for heating or cooling interiors.
In 2019, we completed the construction of the Bayalpata hospital in Achham, Nepal with rammed earth techniques. Bikash, a doctor at that hospital, shared his thoughts about the traditional Nepali architecture of the hospital. He said, ‘The sense of inner peace is always there when we are at the hospital as it reminds me of our traditional home back in the village.’