We are using low-cost effective coating for drought prone houses in rural Kenya to make houses 5x more climate resilient by lowering home temperatures and increasing the thermal mass of housing materials.
We realized that when people had a fundamental asset (like their house) in jeopardy, usually because they were in a disaster-prone region, they were much less likely to make rational decisions around the purchase of poverty-reducing products - like better energy resources and education comparative to people who weren’t in disaster prone regions.
So, we asked ourself: how can we set up the environment such that poverty reducing innovations are accessible to those who could benefit from the most? That's how we landed on housing.
Realizing that Kenya is one of the places where this problem is most prevelant, we came to an important insight.
For every degree change in temperature beyond 29.97 degrees celcius, the strength of houses in rural kenya deteriorates exponentially. So 29.97 degrees is the cracking point of these houses. The interesting thing is that the average temperature in kenya is 29 degrees, so half the time the temperature is actively breaking houses.
Houses in rural kenya generally have 2 main failure points:
- The walls that are typically made out of mud and clay that tend to crack easily when the temperature gets too high
- Strong winds in droughts tend to blow off roofs. Although this isn’t a problem in rural kenya because 82% of the roofs are made up of iron sheets that are durable and robust. The problem with these roofs is that the thermal mass is low. This means that the iron absorbs heat fast and releases that heat too quickly.
Our solution is a reflective coating solution made up of lime-based whitewash with added reflective materials and actively based off white roofs which are currently used in the developed world. It is formulated with locally sourced materials, specifically:
- Lime-based whitewash - it has good reflective properties due to its white color
- Binding agent in the form of plant extracts from local acacia trees - this improves durability
- Fine-grained sand to provide additional durability and abrasion resistance to the coating
- Crushed recycled glass or locally available mica enhance its reflective properties
This solution would provide a 5x increase in drought resilience, which is measured by the thermal mass of the iron vs our solution. We also calculated that the cost of this solution would be KES 8,397.50 (equivalent to 61.91 USD)
To justify the eocnomic investment made in this solution, we calculated our ROI. For every dollar invested in applying this solution to houses in Kenya, approximately $18.12 of value is created through energy savings and improved structural stability.