High in the Cazucá hills, Jasbleidy stands in the doorway of her new home, balancing her 11-month-old son on her hip. On all sides there’s a flurry of activity as student volunteers industriously push seedlings into planters made from plastic bottles. More volunteers pass finished planters up a ladder, slotting them into the grooves of the corrugated iron roof.

Jasbleidy’s two-room prefabricated concrete home was built in a day by a team of volunteers working for the Catalina Muñoz Foundation (CMF). Today, more volunteers have returned to install a roof garden. They are students from a private bilingual school, bussed down for the day from the north of Bogotá. Elsewhere in Cazucá, other teams of students are busy with building work.

The young mother says her new home is a “gift from God.” The woman’s former home was a single room in a concrete block, which she shared with her mother, four-year-old-brother and her son. The squalid surroundings, overcrowding and constant trouble with the landlord over rent made the residence an unpleasant and dangerous place to live.

Jasbleidy first heard about the CMF from her neighbour, who was re-housed by the scheme and encouraged her to apply. “I went to an interview, was selected and within five months we were in our new home,” she says. Because she owns the property outright, her days of dealing with landlords are over. And the lettuce and radishes grown on the roof of the house in 150 planters fed by a simple irrigation system can be used to feed the family, or sell to neighbours.

Working in teams of 10 to 15 and supervised by architects and builders, CMF’s volunteers aim to erect four houses in a day’s work. The houses are simple but solidly built, consisting of two to four small rooms. When the house is finished, a simple key ceremony is conducted; an often emotional event where a grateful family is given their new home.

The brains behind the rooftop garden is Carolina Forero Cortés, who runs the urban gardening programme Techos Verdes (Green Roofs) in conjunction with CMF. At university she experimented with various designs before hitting on the idea of filling 2-litre plastic bottles with earth and placing them horizontally on each roof to grow seedlings.

“This technique has been used before in urban gardening with bottles used vertically, but used horizontally you can grow more than one plant, which increases production,” she said. Foundation resource manager Gloria Pulido says that since the foundation’s beginnings eight years ago 1,517 houses have been built, re-homing 7,585 people all over Colombia.

Gloria says preference is given to families with children under 12, families who are living in crowded households, families with disabilities, and older adults in vulnerable situations. “We also want families who have a strong desire to change and progress in their lives.”

The foundation takes its name from Catalina Muñoz Gómez, who was born in Bogotá in 1996 with a genetic disease called Silver-Russell syndrome. Against all odds – and after nine surgeries and at one point, a two percent chance of survival – Catalina is now a healthy 16 year old.

In 2004, her parents started the foundation with the aim of improving the quality of life of thousands of Colombians in their daughter’s name. As well as addressing the housing deficit in Bogotá’s poorest communities, the CMF works with single mothers, provides education and supplies temporary accommodation. The foundation relies on volunteers from all walks of life to donate their time and energy, and construction companies who donate their materials.