Lime Stabilised Soil for Fire-Resistant Shelter Solutions in Refugee and IDP Camps

Fires are a frequent and deadly hazard in densely populated refugee and IDP settlements. The UNHCR state that in 2021, over 3,000 fires were reported in refugee and IDP camps worldwide, many of which caused loss of life.

A tent in a Syrian refugee camp is destroyed by fire. Shelters in camps are often made of flammable materials.

The world’s largest refugee camp, Kutupalong in Cox’s Bazar, Bangladesh, has endured many devastating fires, including one in March 2021 that destroyed over 10,000 shelters and displaced 45,000 refugees. This is within the context of increased fire-risk caused by climate change, which is worsening the scale of wildfires worldwide as rising temperatures lead to longer and more destructive fire seasons. 

Refugee and IDP camps are particularly vulnerable to fire because of the dense siting of often highly flammable shelters, the widespread use of fire for cooking, either on wood or LPG, and the predominance of camps in countries with hot, dry climates. There is an urgent need to use fire-resistant materials for shelters that can protect lives and restrict the spread of fire, but funding shortages, supply chain issues, political restrictions and fast-paced timescales limit options.

Lime Stabilised Soil offers a low-cost, innovative solution which uses locally available, natural materials which can be mixed and applied by communities themselves. Kutupalong camp, exemplifies the challenges of providing fire-resistant housing in densely populated areas prone to disasters. Here, Lime Stabilised Soil (LSS) is emerging as a transformative building material offering win-win solutions in the most challenging of contexts. 

How Lime Stabilised Soil Enhances Fire Safety

LSS is a mixture of soil, lime, and sometimes pozzolans, which chemically bond to create a hardened material with remarkable fire-resistant properties. It can be applied as a plaster to traditional bamboo, wood or mud structures, and panels of bamboo and tarpaulin, but unlike bamboo and tarpaulin, LSS:

1. Is Non-Flammable: It does not ignite or spread flames, a critical feature in fire-prone environments.

2. Provides Thermal Insulation: LSS slows down heat transfer, helping to contain and minimise fire damage.

3. Withstands Fire Exposure: Tests conducted in Cox’s Bazar showed that while standard shelters burned down within minutes, LSS-plastered shelters remained intact after 20+ minutes of fire exposure. LSS can protect buildings from fires started internally or from external fires and inhibits spread of flame.

LSS plaster is applied to split-bamboo wall panels. Photo (C) Bee Rowan

Why LSS is Ideal for Displacement Contexts

Beyond its fire-resistant qualities, LSS offers advantages that make it particularly suited to refugee and displacement settings:

1. Locally Available and Affordable: LSS relies on natural materials including lime and soil, which are available and low cost in most regions. 

2. In line with regulations: Sometimes host countries have laws prohibiting the use of permanent materials, like concrete, in refugee and IDP camps. As a natural material LSS can align with these regulations while still offering a durable solution.

3. Multi-Hazard Resilience: As well as fire resistance, LSS shelters can withstand monsoon rains and prolonged flood as LSS material remains strong and stable in water.  It also  gives increased thermal performance to the interiors of buildings, keeping buildings cooler in heatwaves and warmer in cold conditions. This makes LSS  a robust material choice for disaster-prone areas.

4. Sustainability: LSS can be carbon-neutral, providing a sustainable  alternative to cement based concrete as LSS  does not contribute to climate change. The use of cement is a global concern - if the cement industry were a country, it would be the third largest emitter of carbon dioxide in the world. 

Success Stories: LSS in Action at Cox’s Bazar

Re-alliance member and LSS expert Bee Rowan worked in Cox’s Bazar with IOM in 2023 on a pilot project to firstly test the viability of LSS in the Rohingya refugee camp context and after evidencing its success, trained teams to build 51 LSS plastered bamboo shelters. She told us how results demonstrated the effectiveness of LSS in addressing both fire and flood risks: 

“We built an LSS-plastered shelter and fire tested it in real-world conditions next to one of the standard bamboo shelters  built on a massive scale in the camps. There had just been a devastating fire in Camp 11 and everyone knew fire prevention had to become a priority as big camp fires were an annual occurrence. . The Rohingya workers  next to me were moved to tears as we watched the LSS building easily withstand 20 minutes of flames without burning, while the standard shelter next to it was engulfed by fire and fully destroyed within 5 minutes.” 

Above - the fire test comparing a standard bamboo shelter (left) to a LSS-plastered shelter (right), both fired at the same time, with the same amount of accelerant and filled with the same calorific loading of flammable materials.  The standard shelter was entirely destroyed. After 20 minutes, when the fuel for the fire had been consumed, the LSS shelter was still intact, except for the bulk of the roof, which was the typical flammable tarpaulin roof. The LSS shelter design has now been adapted to include a fire-resilient LSS plastered roof. Photo (c) Bee Rowan.

Training and Knowledge Sharing

While there is great potential in LSS, further training and knowledge-sharing is needed for its successful and widespread use. To ensure the technology’s broader  adoption, projects need to include training of trainers, and of  local engineers, staff of implementing partners,  community workers, masons and householders.  Investing  resources into training and training of trainers can empower communities to take ownership of the construction process and its quality; creating employment opportunities, fostering resilience and enabling people to maintain and mend buildings far into the future. Bee Rowan has co-authored a Lime Stabilised Soil Construction Guide (available free online, hosted by IOM) which takes readers through the steps needed to build successfully with field-tested lime and local sub-soils. Re-alliance also plans to include building with LSS in their free online course, coming in 2026. 

Lime is slaked with water in a project in Nepal to make lime putty (C) Bee Rowan

A Blueprint for Safer Settlements - improved vernacular design

The introduction of LSS in refugee camp settings can offer a scalable, cost-effective and low carbon solution to one of the most deadly challenges faced by displaced populations. By addressing fire risks, improving resilience to environmental hazards, and aligning with building restrictions, LSS represents a step forward in shelter innovation. For displaced communities, LSS offers a way to adapt vernacular buildings to become safer and more resilient to climate change and its associated disasters. The lessons learned in Cox’s Bazar highlight the potential for this technology to be replicated in other high-risk settings worldwide.