MINNEAPOLIS — Millions of Americans experience homelessness every year, and yet they’re outnumbered by vacant homes and government-owned buildings. A growing number of activists are calling for these empty spaces to be filled with the humans living on America’s streets.

According to the National Alliance to End Homelessness, almost 600,000 people experience homelessness on any given night in the United States as of January 2014. About 15 percent of those people are the “chronically homeless,” while the rest may lose their homes temporarily but find some form of recovery that keeps them off the streets on a long-term basis.

Writing for Amnesty International in 2011, Tanuka Loha, then-director of Amnesty’s Demand Dignity program, put the numbers into a larger, annual perspective, and compared them to the shocking number of vacant homes left after last decade’s financial crash.

“Since 2007, banks have foreclosed around eight million homes. It is estimated that another eight to ten million homes will be foreclosed before the financial crisis is over. This approach to resolving one part of the financial crisis means many, many families are living without adequate and secure housing. In addition, approximately 3.5 million people in the U.S. are homeless, many of them veterans. It is worth noting that, at the same time, there are 18.5 million vacant homes in the country.”

Most empty homes sit vacant after foreclosures, leaving them owned by banks that are loathe to part with them.

The numbers appear to be similar in Europe, according to Rupert Neate, writing for the Guardian in 2014. Neate interviewed David Ireland, chief executive of the Empty Homes charity.

“Homes are built for people to live in, if they’re not being lived in then something has gone seriously wrong with the housing market,” Ireland told Neate.

According to the Guardian, European Union figures show that there are 4.1 million homeless living across Europe, while there are 11 million empty homes across the continent.

Back in the U.S., another report last year highlighted the 77,000 empty government buildings that could be refitted to house the homeless. According to Matt Lemas, writing in Ryot, while some existing legislation allows for these kinds of conversions, it requires local pressure and pro-active legislators to be effective.

“In San Francisco, for example, the city passed the Surplus Property Ordinance in 2004, which gave the Mayor’s Office for Housing the jurisdiction of vacant lots so they could be developed into shelters for homeless people,” Lemas wrote. “Additionally, in Seattle, a homeless grassroots group called Operation Homestead re-opened abandoned apartment buildings and turned them into affordable housing for formerly homeless people.”

In October, the Atlantic reported that activists in Baltimore are pressuring lawmakers to house that city’s 30,000 homeless in its estimated 16,000 empty homes. “Clearly there’s a moral crisis when you see so many people in need of homes and there’s such a glut of vacant ones,” said Rachel Kutler, an organizer with United Workers.

And in April, Utah announced it has almost eliminated chronic homelessness through a pioneering program to put the homeless in vacant apartments, then provide them with social services like drug rehabilitation after they are safely housed.

“[O]fficials announced that they had reduced by 91% the ranks of the chronically homeless — defined as someone who has spent at least one year full-time on the streets — and are now approaching ‘functional zero,’” according to John M. Glionna, a national reporter for the Los Angeles Times. “In 2005, when state officials began placing people in permanent housing, they counted 1,932 chronically homeless. Today, with 1,764 people housed, that number has plummeted to just 178 statewide. And officials have their sights set on those remaining.”

Overall, data from the National Alliance to End Homelessness suggests the homeless population, defined as those who sleep on the streets or resort to shelters, has decreased since 2007. But the same figures look far less positive after factoring in the number of people who still lack homes of their own. According to the alliance, “The number of poor people living doubled up, has grown substantially over the last several years. These are people who are housed, but not living independently in their own homes. This is a symptom of the affordable housing crisis in this country.”

Watch “Housing is a Human Right,” a presentation by Sczerina Perot, a human rights lawyer, at TEDxASL (American School in London) 2013: