Mexican housing must become denser and better planned to provide adequate living options to lower-income parts of the population, according to a new study, which said the country's current residential construction was largely unregulated.

"The real problem is providing housing to the bottom 20% or 30%," said Albert Saiz from the Massachusetts Institute of Technology (MIT).

According to Saiz, the prevalence of self-built, one-family homes is a bigger problem than growing numbers of "digital nomads" - remote workers living in Mexico but earning disproportionately large salaries from abroad - which have been the focus of criticism since the coronavirus pandemic took many jobs online.

The study argued that, to meet the population's needs, Mexico's urban housing must become three or four times denser than current levels, meaning that one- to two-story housing should be replaced by multi-level apartment buildings.

It also found that more than six in ten new builds are constructed by owners, not developers, and are largely unregulated.

"We're talking about a market where, you know ... 40% or 50% of people have access to credit," Saiz said.

With credit penetration on the rise but still low, many Mexicans, unable to apply for mortgages, turn to building their homes themselves, Saiz said.

"In the next 20 years, hopefully, 0% of homes are self-produced," he said, instead arguing for more formal, regulated construction.

Colombia, which is also a focus of the study, had seen success with social housing programs and could be a template for Mexico, Saiz argued. Social programs in Mexico had until now largely offered housing only to a few, mostly middle-class groups, he said.

"Now (Mexican policymakers) need to extend that template and devote the resources for the bottom 20%," he said.

La Haus, a Colombian company that buys and sells housing and provides a marketplace for others to do so, supported the research.