ARGENTINA • Jesus Ponce celebrated his 18th birthday with a cake given to him by a family whose toilet he was building.

Jesus lives in Florencia Varela, a town in the south of the province of Buenos Aires, with his five brothers and his father. Four months ago, they finally got a bathroom and kitchen, thanks to an initiative by Horizonte de Maxima. To show his gratitude, he decided to volunteer to ensure that other families could have the same.

"Just as they helped me, now I can help others. It was nice to meet the family that we are building for... they came in with a cake to celebrate my birthday," he said. Through the project, Modulo Sanitario, Horizonte de Maxima seeks to resolve the sanitation needs of families living in informal settlements, and contribute to their health and hygiene.

According to the 2010 Argentine national census, six million people do not have a bathroom. By April, 61 units had been installed and the idea is to build 100 more this year. How did the project come about? Mobilised by the great social inequality that exists in Argentina, eight university students from both technical and humanitarian backgrounds worked with vulnerable families to design a dignified, low-cost and easy-to-assemble sanitation unit.

In these settlements, almost every household has an outside bathroom, with walls of sheet metal and no roof. The group equips kitchens with a sink and tap with hot water. The bathroom unit consists of a sink, tap, shower and toilet. The cost of each unit is US$1,500 (S$2,080) and the family is asked to contribute US$125 to make the cesspit required for the construction and installation. The remaining US$1,350 comes from Horizonte de Maxima, which raises this money primarily through individual and business donations.

Correction note: This story has been edited to correct the cost of each unit, the amount the family is asked to contribute, and the amount provided by Horizonte de Maxima.