The improvised shacks seen in many parts of this southeastern Brazilian metropolis have extended upward and now contain as many as eight stories with uneven walls, exposed brick and roofs made out of metal sheets.
Such is the case in Sao Paulo's largest favela (shantytown), Heliopolis, which is located less than 10 kilometers (six miles) from the city's business district, the most important financial center in Latin America.
The need to find space to live in a city with an enormous housing deficit has led to an increase in these precarious "do-it-yourself buildings," which reach ever higher into the sky in a metropolitan area that is home to an estimated 20 million inhabitants.
The birth of a new child, a relative returning home or a marital separation are some of the reasons why Heliopolis' residents gather up material and get to work on their home renovations despite a lack of proper qualifications or technical supervision.
Every new "puxadinho," as these informal annexes are known, tell a family's unique story and ensure that no two houses are alike in that favela, Sao Paulo's largest in area (around one square kilometer) and second-largest in population (210,000 inhabitants).
Sandra Regina dos Santos, 61, told EFE that she arrived in Heliopolis "when it wasn't Heliopolis yet."
"There was nothing but weeds, no water nor electricity," she recalled.
In 1976, her husband Jose Mariano spent just five hours building a wooden shanty that served as a makeshift shelter for the couple and their seven children (as well as an eighth who was "on the way").
"There was just one mattress lying on the floor, Sandra said smiling.
Over time, a sturdier construction made of bricks and plaster was built, and today a three-story dwelling measuring 200 square meters (2,150 sq. feet) sits on the original site and provides a home shared by nine members of the family.
"This is the first piece of furniture I ever bought," Sandra said proudly as she walked through the kitchen and pointed to a shiny brown and gray cabinet she purchased several months ago.
The cabinet stands out amid other old furniture resting up against the walls, which are only partially covered with tile.
"We didn't have more, but we'll finish (covering the walls) soon," Sandra said.
This family's house, like many others, was renovated by Habitat for Humanity, an international non-governmental organization that works on Heliopolis' most precarious homes.
Rene de Castro, an architect who supervises home-improvement projects in the region, said that in recent years some entrepreneurs have arrived in the favela looking to capitalize on the low cost of land.
He said they have been putting up buildings with as many as eight stories and renting them later at nearly market prices.
"We can talk about real-estate speculation," De Castro said, warning of the danger that residents who came to Heliopolis because they couldn't afford to live elsewhere will fall victim to gentrification and be forced to move a second time.
The architect said the accumulation of high-rise dwellings in shantytowns is a symbol of the severe housing deficit in Brazil, a country that has a shortfall of six million homes.
The housing councilor of Sao Paulo, Joao Farias, acknowledged that housing remains a major challenge in a city where an estimated 1 million people live in favelas.
He said that a few days ago the city government signed a public-private partnership for the construction of social housing, an initiative that aims to erect 40,000 units by the end of 2020.
Farias said the city's budget for social housing policy amounts to just $148 million this year, or less than half the $370 million allocated for city maintenance.
He said that due to a lack of funding it is imperative that the federal government, headed by rightist President Jair Bolsonaro since January, define its housing policy soon.
Although Heliopolis, whose homes continue to rise upward in a spontaneous and uncontrolled manner, faces an uncertain future, Sandra Regina dos Santos said it will continue to be her home.
"I don't see myself in another place," she added.
One of her daughters who lives in the three-story house, 25-year-old Juliele, is thinking in the short term.
"I think another floor can be built," she said while looking up at the still-untiled kitchen ceiling.