Student loan debts have emerged as yet another hurdle to a housing recovery.

A good amount of the literature today on the housing market focuses on the various things that “hold housing back.” From tough lending environments to excess inventory, the topic is a common one, and all the reasons, from foreclosures to lackluster construction, are often the same.

New research from Rick Palacios, though, of John Burns Real Estate Consulting, covers a heretofore unmentioned topic in the housing media echo chamber – surging student debt, and the way it inhibits investment for college graduates.

Palacios writes that student loan debt is now at $865 billion, an average of $25,000 per student that outweighs all other kinds of household debt, excluding mortgage debt (even credit card debt is less than student loan debt).

Such debt, he concluded, stifles all possible housing investment from the 25- to 34-year-old demographic, and Palacios cites some frightening data to support his claim.

For instance, with student debt as high as it is, six million graduates in the aforementioned demographic have moved back in with their parents, a 26 percent increase from when the recession began in 2007; complementing that is the homeownership rate for 25- to 29-year-olds, which at 36.8 percent is the lowest since 1999 (and for 30- to 34-year-olds, it’s at its lowest rate in 17 years).

And to top it all off, with the poor job market, student loan defaults have doubled, and with such data on a two-year lag (only data through 2009 is currently available), the statistics may get even worse.

So in short, recent college graduates are out of work, living at home and buried beneath a mountain of debt. Even with mortgage rates at historic lows and housing affordability at record levels, the vast majority of graduates simply cannot take on any more debt.

Palacios does, however, highlight one promising nugget hidden deep within such negative data – future growth.

“The good news is that this pent-up demand will ultimately provide a much needed boost to the housing sector,” Palacios wrote.

The one caveat, though, is that all that pent-up demand will not necessarily go into housing. Rather, Palacios projects that throughout the next three years, renting will continue its ascent to a projected 46.8 million households in 2015, nearly 13 million more than in 2005.

“That the boost will be heavily skewed to the rental market, as it will take longer than ever for young people to qualify for a mortgage, especially if more and more graduates are hit with credit blemishes from unpaid student debt,” Palacios wrote. “All of this analysis contributes to our belief that the lion’s share of housing demand will end up in the rental market.”