Freddie Mac released its weekly update on national mortgage rates this morning, reflecting continued declines in the cost of getting a loan to buy a home.

For the fifth week in a row, 30-year fixed rate mortgages (FRM) declined, falling five basis points, to 3.35%. Shorter-term 15-year FRMs also dropped five b.p., to 2.56%. Curiously, this is the precise rate now attached to both variable 5/1 ARMs, and one-year ARMs, as well -- 2.56%.

Result? Getting a mortgage where the rate cannot rise for the next 15 years now costs no more than a rate fixed for only five years ... or for one.

Commenting on the numbers, Freddie Mac vice president and chief economist Frank Nothaft linked the across-the-board declines to "the release of the advance estimate of real GDP growth for the first quarter of the year, which rose 2.5 percent but fell short of the market consensus forecast." On the plus side, Nothaft predicted that "near record low mortgage rates should further drive the housing market recovery over the near term."