Low-cost shelters speed behavior change

Posted in — Cambodia Sanitation > Design
March 11, 2019
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A “Ring Shelter” example being advertised with prices at a latrine business owner’s facility. (Photo by Glen Engel-Cox/iDE/2018)
iDE Global WASH

By designing lower-cost shelters, iDE hopes to accelerate latrine use in rural locations.

The lack of a superstructure (shelter) can often mean the difference between a latrine that’s been purchased and one that is actually used, given that households prefer to use their new latrine after a permanent shelter has been installed, rather than use it with a makeshift shelter (See “Removing barriers to immediate installation and use”). To lessen the time between latrine purchase and shelter purchase, iDE designed a low-cost shelter that could be used with the Easy Latrine. Even though iDE’s Easy Shelter, a brick and mortar option, was designed to be extremely affordable, it is a significant increase (up to seven times) from the cost of the latrine substructure alone. While finance options could help some households (e.g., by being able to extend payments over time, rather than having to have the entire amount at once), iDE also wanted to explore lower cost designs to reach more households.

To further reduce costs, iDE initially experimented with shelter designs using cheaper materials than the bricks and mortar used in the Easy Shelter. Traditional shelters of bamboo and palm leaves did not match household’s aesthetic aspirations for their new latrine, so iDE decided not to promote them. iDE also tested a slightly more expensive option that used zinc metal sheeting over the bamboo/palm frame, and while this was more sturdy and weatherproof, it also failed to meet aspirations. A new design that seemed initially promising used PVC piping and canvas in place of bamboo and grass. Prototype testing, however, indicated that users felt the walls were “flimsy” and that access to the latrine was awkward.

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Installing an Interlock Brick latrine shelter. (Photo by iDE/2015)

However, two additional designs did prove to be more attractive to households. One design—the Ring Shelter—used the same type of concrete rings that lined the latrine pit. Three rings were placed one atop another around the latrine with a door cut into the side. At about half the cost of the Easy Shelter, it still required a mason to mortar the seams and connect to the base. This design was so popular that businesses not connected with iDE reverse engineered how to construct the Ring Shelter and began selling it to their customers.

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Proud client Nguy Chreah stands in the doorway of her newly installed Interlock Shelter. (Photo by Sophy Phann/iDE/2017)

The other design that caused the most excitement was the emergence of the Interlock Shelter. Based on pressed bricks that fit together similar to children’s construction toys, the interlocking brick construction was originally tested to address the need for slightly larger, customizable shelters to accommodate users with disabilities (see “Designing accessible latrines”). However, the reduced cost of these bricks compared to kiln-fired bricks, and the fact that the shelter could be constructed without the need for a trained mason, meant that an Interlock Shelter could be purchased for about 20-25% less than an Easy Shelter. The current limitation on promoting the interlocking bricks is the amount of time it takes to make the bricks themselves. iDE is investigating how to scale up brick manufacturing to meet this new demand.