Minneapolis-St. Paul does not have the cheapest housing stock in the nation, but its higher wages make it the most affordable region for homeownership among the 25 largest U.S. metro areas, according to a new report.

Interest.com calculated its new rankings based on several criteria. The study found that the median household income in the Twin Cities is a little more than $67,000 — nearly $15,000 above the national average — and the median-priced home is nearly $213,000.

The margin isn't as great as last year, but the median income in the Twin Cities exceeds the wage requirements for purchasing a home by 23 percent. These figures, when combined with median property taxes and homeowners insurance rates — both of which fall in the middle of the pack — helped lift Minneapolis-St. Paul from the No. 2 spot in 2013 to No. 1 this year.

"The places that are the most unaffordable are locked in by some geographic constraint." The Minneapolis area "can grow 360 degrees. Most of the time when you talk about this, you talk about sprawl and you think of it in negative terms. But the bottom line is, sprawl keeps your prices down," said Mike Sante, managing editor of Interest.com.

Atlanta won the crown in 2013 but swapped rank with the Twin Cities in 2014. St. Louis, Detroit, Pittsburgh, Baltimore, Phoenix, Washington, Dallas and Houston rounded out the top 10.

Well positioned, for now

"We are now kind of in that sweet spot, where we have low interest rates, lots of good houses coming on the market and, believe it or not, credit is starting to loosen up a bit," said Emily Green, president of the Minneapolis Area Association of Realtors.

The Interest.com study also suggests median-income workers cannot afford a home in the remaining large metro areas because wages don't match real estate costs.

San Francisco, notorious for steep housing costs, has the worst wage-to-price ratio, with San Diego, New York, Los Angeles and Miami also receiving "F" scorecards, the letter-grade system used in the rankings. Coastal cities like these do not have the option of "360 degrees" of growth afforded to the Twin Cities. It is not uncommon for Bay Area residents to spend half of their income on rent, Sante said, with some people spending as much as 70 percent, which makes the dream of homeownership unattainable.

Moving up from the bottom, other unaffordable cities are Boston, Seattle, Sacramento, Denver, Portland, San Antonio and Tampa.

Income growth is key

"Low mortgage rates are helping home affordability to some extent, but the key ingredient — which has been missing to this point — is substantial income growth," Sante said in a statement.

For comparison, the median-income earner in Minneapolis-St. Paul may make about $10,000 less than the median-income earner in San Francisco. But, the median-home price in the Twin Cities is $213,000 to San Francisco's $770,000, a gap too great for that wage difference to close.

Sante said Minneapolis-St. Paul has a great housing market with better median-priced inventory than other cities but said wages have to keep growing.

Year-over-year wages grew by an average of 2 percent across the 25 largest metropolitan areas, but the Twin Cities only grew 1.38 percent in 2013.

"If that continues, homes in the Twin Cities will be much less affordable in a decade," Sante said.