Rising prices in much of the United States caused the house affordability to drop slightly, according to the new National Association of Home Builders/Wells Fargo Housing Opportunity Index.

The newest index showed 73.8 of all new and existing homes sold in the second quarter could be purchased by families earning the nation’s $65,000 median income. The figure is down from the record 77.5 percent of houses that were deemed affordable in the first quarter of 2012.  

The NAHB said 92 percent of metro areas saw house prices rise.

"While interest rates and overall housing affordability remain very favorable on a historic basis, the decline in the latest HOI is a positive development because it is another signal that the housing recovery is starting to take root, and it lends needed confidence to prospective buyers and sellers who have been reluctant to move forward in the current marketplace," said NAHB Chairman Barry Rutenberg, a home builder from Gainesville, Fla.

The market with the most affordable housing market was Youngstown-Warren-Boardman, Ohio-Pa., according to the index. An estimated 93.4 percent of homes there were affordable to families earning $55,700, the region’s median income.

The least affordable market was New York- White Plains-Wayne, N.Y.-N.J. Only 29.4 percent of families with a median $68,300 income can afford a home in the New York City metropolitan area.