Kwangu Kwako vs Mabati : The Ultimate Fire Test

The Kwangu Kwako Fire Test

The Kwangu Kwako journey was originally inspired after our co-founder Simon witnessed a destructive fire in Mukuru slum. While not uncommon, this one struck him particularly, having co-workers who were affected by the fire that day. But what really pushed him to take action wasn’t the fire itself; surveying the aftermath of the fire, Simon noticed the only buildings left standing amidst the rubble were two pre-cast concrete toilets. He decided right then and there to apply that model to homes, so that his co-workers and other families of informal settlement communities would be protected against these unforgiving fires.

Our model is centred around providing better housing in a cost effective way, enhancing safety, security and dignity to families. One primary focus is reducing the impact of fire and the spread of fire. However, unlike the toilet example, our homes (thankfully) have yet to be exposed to such a disaster. We wanted to put our model to the test, and what better way to do this, than by creating a fire ourselves! We had our engineer, Chris, craft together 4 mini model homes for the big day; two Kwangu Kwako homes, and two mabati homes, all lined up and ready to burn!

Four models built for the fire test. From left to right: KKL Home#1, KKL Home#2, Mabati Home#1, Mabati Home#2.

Each miniature home was filled with materials you would find in a typical home in Nairobi’s informal settlement communities, scaled down to size:

  • Mosquito net mesh
  • Foam for the bed and furniture cushions
  • Bottle of water (representing water jugs families have for everyday use)
  • Wood, clothing pieces, papers and a small amount of kerosene (for furniture, personal possessions and flammable materials for cooking and lighting purposes)
  • Plastic (representing water jugs and other storage containers)
  • A lit candle (for lighting, but also to observe the effects of smoke within each unit, as an indication of the level of oxygen in the air)
Left side of the interior, showing mosquito net, paper, foam, water bottle and concrete test piece.
Right side of the interior, showing wood, candle and pieces of clothing.

We had a pretty good idea of how the mabati homes would react to the fire; what we really wanted was to observe how our precast concrete alternative would hold up in the event of a fire. So we designed two tests for the day:

Fire Test #1 (AM): Lighting KKL Home #2 on Fire

For our first test, we lit one of our own homes on fire. By lighting KKL#2, we could observe how our adjacent KKL home was affected by the fire, while also monitoring the impact a fire from our home might have on an adjacent mabati. Our hypothesis was that the fire would be self-contained, not spreading to and destroying the adjacent homes.


  • Observe the growth of the fire, timing the whole process
  • Monitor any spreading of fire to the adjacent homes
  • Investigate the damage caused to the home and adjacent structures due to fire and smoke
  • Check the structural integrity of our home after the impact of a fire
  • Test how our roof structure and frame reacts during a fire
  • Test how the metal rods of our model affect the concrete around them when exposed to the extreme heat of a fire

Fire Test #2 (PM): Lighting Mabati Home #1 on Fire

In the afternoon, after the debris from the first test had been cleared away and the home reconstructed with the same materials, we lit the mabati home#1. Again, we wanted to observe how the fire would react and affect the adjacent structures, particularly what damage these neighbouring homes would incur. Our hypothesis for this test was that the fire would spread to the mabati home#2, but that the KKL home#1 and 2 would remain undamaged.


  • Observe the growth of the fire, timing the whole process
  • Monitor any spreading of fire to the adjacent homes
  • Investigate the damage caused to the home and adjacent structures due to fire

So What Happened?! Major Takeaways

The results are in folks! The fire test was a ‘flaming’ success!

We successfully proved that our homes are a safer alternative to mabati structures when it comes to preventing the spread of fire and reducing the damage caused by fire in informal settlements. There were also a few pleasant surprises that left us feeling proud and even inspired by our own housing solution.

Fire Test #1

KKL home#1 unscathed by the fire raging in KKL home#2.
KKL home#2 burning beside Mabati home#1, undamaged.

Our KKL home exceeded expectations when exposed to fire. Despite the raging fire inside, the flames were contained to home#2, with no spread to adjacent structures. There was a bit of smoke damage to the two neighbouring homes, which is expected, but not enough to make them uninhabitable. What’s more, none of the heat-sensitive materials in the adjacent houses (such as the mosquito net, wax from the candle, foam or paper) were damaged at all, meaning the temperature in the houses next to the fire remained relatively mild. In fact, we took some temperature readings during the test, with some unexpected results:











While the temperature inside the burning home climbed, the water bottle in KKL home#2 burst, melting into itself. Eventually, this caused the water inside to start boiling; that’s at least 100°C! Meanwhile, KKL home#1 remained cool to the touch, with a temperature recording of 24°C; that’s cooler than the outside temperature at the time, which was 29°C!

We also had an unexpected tenant in the home; after 8 minutes of raging fire inside KKL home#2, a small gecko emerged from the flames! He came out of the burning, smoking house, looked left at the mabati house, then right to our adjacent house, and very quickly made the decision that the KKL house was safer. You could say we got the gecko seal of approval!

Gecko crawls out of the flaming KKL home#2 and escapes into KKL home#1 for shelter.
Metal rod test pieces before and after exposure to fire when placed one in each corner of KKL home#2.

After about 20 minutes of excitement and anticipation, the fire had died down and eventually put itself out. We are thrilled to report that overall, the structural integrity of our pre-cast concrete home remained! We had also placed test pieces in all four corners of the home, pre-fire which further reinforced this finding – even on the most damaged specimen, the concrete around the rod did not crack or damage after exposure to the direct flame. This proves that the rods don’t expand to crack the panels in the event of a fire.

Overall, the main damage incurred during the fire test was the roof and its timber frame. This was also expected, given the materials used. While the roof needed replacing, the fire still did not spread to the neighbouring roofs, which was quite impressive.


Fire Test #2

After lighting mabati home#1.

It quickly became obvious that the second test would be much more eventful than the first (and much less disappointing for the inner pyros of the team)! After a mere 1.5 minutes, the fire of mabati#1 had spread to the adjacent mabati#2 and set it ablaze.

Fire spreading to mabati home#2 after 1.5 minutes.

Despite the growing fire, our precast concrete models were not affected! We could not have been more thrilled with the resistance to fire that our homes offered. While the timber piece closest to the mabati#1 was damaged and would need replacing, overall the roof remained intact. What’s more, there was no damage to the materials inside the concrete homes whatsoever.


Fire test #2 raged for quite a bit longer than the first, with the worst of the fire lasting for over 10 minutes. When the fire eventually died down (approximately 45minutes), both mabati structures were in ruins with nothing salvageable for re-building.

End result of fire test #2.

What’s Next?

We are excited to continue testing our model after making a few adjustments. Even though our pre-cast concrete homes were able to withstand exposure throughout both fire tests, the roof did not. While this was expected, given the materials used, we would like to test a metal roof solution for our homes, so as to further enhance the safety features we can provide to families living in informal settlements.

We would also like to carry-out a full-scale fire test with real materials and furniture inside the homes. While this test has provided us with confidence regarding the response of our model to fire exposure, there were a few limitations that can only be resolved using a full-scale model, simulating a real life scenario. For example, the timber frames of the roof and mabati structures were not to scale in this test, which made for longer burning times and longer structural integrity (particularly in the mabati homes) than we would expect in a full-scale test. This might also have influenced the damage to adjacent roof frames between KKL#1 and mabati#1 during both tests. In addition, a life-sized experiment would allow us to further test the overall impact on the structure of our buildings which, in reality, are stacked 4-5 panels high. Finally, although we did test the impact of heat on the rods using the 4 test pieces in fire test#1, this is not sufficient to understand how the structure would react under these same conditions while stacked high.

Final Thoughts

The Kwangu Kwako Team. From left to right: (top) Simon, Erastus, Symon; (bottom) Chris, Winnie, Melanie.

Overall, the results could not have been better for our first fire test, leaving us to wonder what took us so long to set this up in the first place! We were ecstatic to confirm the added value we offer to families living in informal settlements, and confident in our claims of providing safer homes for those in need. The Kwangu Kwako solution is clearly a small investment with huge impact potential for these communities, where the threat of fire is ever-present, extremely destructive and hinders development in these environments. As the Kwangu Kwako team, we are so proud to offer our homes as a solution to one of the many risks these communities face.

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