The constitution of Paraguay states that “every inhabitant of the Republic has the right to decent housing facilities.” Ratified in 1992 following decades of brutal military dictatorship, the document remains aspirational for the landlocked country, one of the poorest in South America. In the capital, Asunción, less than a mile east of the cabildo, where these words were drafted, is the neighborhood of La Chacarita, an assortment of informal settlements on the rugged bluffs overlooking the Paraguay River. In local slang, the word chacarita could be translated as shantytown, and the housing there is reminiscent of Brazilian favelas: jerry-built shacks of simple industrial materials, such as concrete blocks and corrugated metal, along narrow and winding pedestrian paths that are impassable for emergency vehicles.

In 2019, the Ministry of Urban Development and Housing (MUVH) invited New York City firm MOS Architects, a 2008 Design Vanguard, to enter an international competition to design public housing in La Chacarita. The scope of the project, which would be funded in part by an investment of $14 million from the Inter-American Development Bank, included a total of 37 acres of flood-prone land straddling existing canals. Rather than causing displacement, the development would house the families who were already occupying the sites. After a delay caused by the pandemic, in 2021, the project was awarded to MOS, which invited Buenos Aires, Argentina–based Adamo-Faiden to serve as design collaborator and nearby liaison, and local firm Equipo de Arquitectura as architect of record.

The reason the Paraguayan government would reach out to an American office known more for its expansive bibliography than for its catalogue of built works is twofold. “My understanding is that everybody in the country has made proposals for the site, and it has been used many times as the focus of studios and for student projects,” explains Hilary Sample, MOS principal and cofounder along with Michael Meredith. “That became a challenge, because how do you pick a local architect without upsetting everyone?” But more importantly, the government was looking for a new approach, and MOS has been researching and rethinking housing since its founding two decades ago.

For one of the first major exhibitions the firm participated in, Foreclosed: Rehousing the American Dream at the Museum of Modern Art in New York in 2012, MOS reconsidered suburban streets as linear housing. In 2016, MOS proposed low-rise, high-density developments to revitalize Detroit for The Architectural Imagination, the U.S. pavilion at the Venice Biennale. And in 2019, MOS completed Laboratorio de Vivienda, a master plan in Mexico City for 32 experimental low-cost housing prototypes designed by various internationally renowned architects. Most recently, MOS published Public Spaces NY the second in a series of books on urbanism and housing, which proposes novel forms of cohabitation in cities.

Building on these ideas, the design for Chacarita organizes 38 discrete towers raised above the flood level on plinths. The position and orientation of each of these roughly 22-by-22-foot, four-story towers adapt to the specificities of the sites, while the plinths follow the irregular contours of the topography, rehabilitating the ravines, managing stormwater, functioning as retaining walls, and integrating much-needed plumbing and electrical infrastructure. Each tower is also capped with a walled-in private roof terrace. Through this configuration of clustered housing towers, the project creates a linear park of semiprivate terraces, mango-tree-filled gardens, and pedestrian routes.

The materials are uniformly economical and rely on construction methods common to the region. The towers are built with a minimal concrete frame encased with local brick—while not specified in the design, the government sourced bricks from multiple suppliers, leading to subtle color variation among the towers. Inside, the floors and ceilings are ceramic tile, and the walls are white plaster. The buildings are unconditioned (though some residents have already added mechanical units), relying on the thermal mass of the brick, natural ventilation, and a solar chimney effect in the stair cores to maintain comfortable conditions in the subtropical climate.

The 78 apartments are necessarily spartan, due to the limited budget, but MUVH conducted interviews with each of the long-term occupants of the sites early in the design process to ensure that the residences would meet their specific needs. Some recurring themes emerged: few wanted more than two bedrooms, many requested large kitchens as the primary room for family gathering, and access to outdoor spaces was a prominent concern. “What makes this project different, moving it out of the realm of the universal for housing, is that it is much more local, specific, and tailor-made,” says Sample. “That’s really exceptional for social housing.”

MOS is well aware of the fraught history of social housing: from Robin Hood Gardens by Alison and Peter Smithson to Pruitt-Igoe by Minoru Yamasaki, the best architects with the best of intentions have too often fallen short. The design of Chacarita, its holistic approach to the site, and its effort to center the residents in the process can be understood, then, as a polemic added to an ongoing discourse. “Throughout modernism, housing was thought of as something universal and adaptable everywhere, but it’s really not,” explains Sample. “We know housing is more successful the more it is adapted locally.”

The government came to MOS for something new, and, speaking to local newspaper La Nación upon the completion of the first phase of the project, the head of MUVH, Juan Carlos Baruja, framed the development not only as an advance for La Chacarita but as a major milestone for the country’s housing policy and a model for fulfilling its constitutional mandate. In 2025, the project received a Holcim Foun­dation Award for its community-driven and reparative approach to the site. But, as Sample acknowledges, “housing requires a much wider window and a much longer view,” and Chacarita’s ultimate success will be measured over decades in how it lives up to the evolving needs of the people who call it home.

Images courtesy MOS Architects; click to enlarge