Nationwide housing affordability during the first quarter rose to its highest level in the more than 20 years it has been measured, according to a recent report from the National Association of Home Builders (NAHB).

Nearly three-quarters (74.6 percent) of all new and existing homes sold nationwide in the first quarter were affordable to families earning the national median income of $64,400, according to a statement. This beat the previous high of 73.9 percent set during the fourth quarter 2010 and marked the ninth consecutive quarter the index has been above 70 percent. Until 2009, the housing index rarely topped 65 percent and never reached 70 percent.

"With interest rates remaining at historically low levels, today’s report indicates that homeownership is within reach of more households than it has been for more than two decades," said Bob Nielsen, chairman of the NAHB. "While this is good news for consumers, homebuyers and builders continue to confront extremely tight credit conditions, and this remains a significant obstacle to many potential home sales."