Purchasing a home is currently the most affordable it has been for the past twenty years.

Thanks to a continuing fall in home prices and record low mortgage rates, the National Association of Home Builders/Wells Fargo Housing Opportunity Index has hit a record low level of affordability.

According to this index, 75.9% of all homes, both new and existing, sold during the three month period ended on Dec. 31 could have been purchased comfortably by families earning the national median income of $64,200.

That percentage was the highest recorded in the 20-year history of the index, and a sharp rise from just three months earlier when only 72.9% of all homes sold were considered affordable.

However, being able to afford a home and actually being able to buy one are two entirely different matters. According to Barry Rutenberg, chairman of the National Association of Home Builders (NAHB) and a home builder from Gainesville, Fla., potential home buyers are still having difficulties landing mortgages.

Mortgages are cheap but you may not be able to get one

"While today's report indicates that home ownership is within reach of more households than it has been for more than two decades, overly restrictive lending conditions confronting home buyers and builders remain significant obstacles to many potential home sales," he said.

Those who are able to land mortgage though, will be able to take advantage of rates that seem to hit a new low every week. This week interest rates for 30-year loans averaged a record low of 3.87%, according to Freddie Mac.