Low home prices and mortgage rates combined to bring housing affordability to its second-highest level ever, according to a new report from the National Association of Home Builders.

For the third quarter of the year, the association's Housing Opportunity Index rose to 72.1, indicating the percentage of homes sold that were affordable for those earning the national median income of $64.400. That mark was just below the all-time low of 72.5 percent from early last year, and it was the seventh straight quarter above 70.

"With interest rates remaining at historically low levels, and house prices starting to stabilize, homeownership is within reach of more households than it has been for almost 20 years," said NAHB chairman Bob Jones.

Housing affordability has remained high even as personal incomes have failed to grow. According to the Department of Commerce, the average personal income dropped by 0.1 percent in September.