BUENOS AIRES — Urbanites are familiar with homeless people pushing supermarket carts around the streets with their belongings inside. But now an Argentine architect has designed a one-man shelter around such carts, providing the homeless with a small room they can wheel around with them. The American Institute of Architects and the Atlanta-nonprofit Mad Housers even awarded a prize for the creation of this so-called "rolling shelter."

Yet Eduardo Lacroze's design is not without controversy, as critics suggest that his shelter only condemns homeless people to intolerable circumstances. Still, the "rolling shelter" could work perfectly in Buenos Aires, where about 1,200 people are thought to sleep on the streets. Manuel Lozano of a local NGO, Funcación Sí, says the number grows when considering those who have virtually no options.

"To those effectively sleeping on the street, you would have to add those in provisional accommodation, hostels, hotels or those on housing subsidy," Lozano says. "That is, people with precarious housing solutions."

The number of homeless people is growing in Argentina, though the problem is worse in the United States and is increasingly becoming a global issue.

The rolling refuge "grows" around the typical supermarket cart like an enormous boxy rucksack. The shelter hangs on the sides of the trolley, and when it's parked, opens sideways to create a sleeping space. It's made of reinforced plastic panels with air cells inside that improve the thermal insulation. A sleeping bag fits inside it. Its advantage, Lacroze says, is that it "resolves in a single element the issues of roof and storage for a homeless person."

He hopes to mitigate production costs with trolley donations from supermarkets. A unit currently costs $500. He is soliciting U.S. government help to build a number of these shelters to offer them on the streets to the homeless. "You could organize a system like bicycles," he says. "People would take them out of the shelter when they need one and take it back when they're done."

Photo: Lacroze-Miguens-Prati

Homeless people are a symptom of segregation inside big cities and victims of seemingly irredeemable economic and social marginalization. There are numerous, complex reasons why so many end up on the streets: addiction, family abuse or mistreatment, mental illness, extreme poverty and abandonment, among them. In all such cases, the person concerned has lost all social and family safety nets.

Critics say that this "solution" of mobile shelters will merely prolong the plight of the homeless, rather than solve it. Lozano responds that he is "just glad someone has started to think about how to improve the conditions of people living on the street." He says that condemning him for the idea is like "accusing a doctor of interrupting bleeding first before attending to what caused it."

After winning an award for his creation, Lacroze sought financing and company interest in making his prototype in large quantities. "Ground-level organizations like Mad Housers, which commissioned the project, are very skeptical about what public institutions and corporations can do," he says. "Our effort involves building a bridge with them."

It was the mobile and provisional nature of the concept that most caught the attention of the prize-giving jury, which included architects, industrialists and homeless people.

"They saw the shelter more like a suitcase than a house, as something more accessible, which people can maintain and take around," he says. "A first step toward a definitive solution."