No. 1 least-affordable U.S. city: San Francisco If you're going to San Francisco, be sure to wear some flowers in your hair -- and put lots of money in your wallet. That's because Interest.com found that the City by the Bay has the absolutely worst housing affordability of any major U.S. metro area. San Francisco's $71,975 median household income trails only Washington's as the highest among major cities, but it's still 32.8% too low to allow a typical family to qualify for a mortgage on a median-priced home. Sante says San Francisco is unaffordable mostly because it has the nation's most-expensive properties: $552,600 for a median-priced home. "Again, it's all due to limited land," he says. "You're hemmed in by the Pacific Ocean and bay, and concerns about earthquakes limit the density of the housing that you can develop." Interest.com also found that the typical San Francisco homeowner faces an above-average $922 in annual insurance premiums, plus a median $4,991 in property taxes -- second only to New York as the nation's steepest annual bill.