Freddie Mac has released the results of its Primary Mortgage Market Survey (PMMS), showing average fixed-rate mortgages (FRMs) changing little over the past four weeks which is helping to spur new home construction, as the 30-year fixed edged up to 3.56 percent, while the 15-year fixed remained unchanged at 2.77 percent. The 30-year FRM averaged 3.56 percent with an average 0.8 point for the week ending Feb. 21, 2013, up from last week when it averaged 3.53 percent. Last year at this time, the 30-year FRM averaged 3.95 percent. The 15-year FRM averaged 2.77 percent with an average 0.8 point, the same as last week. A year ago at this time, the 15-year FRM averaged 3.19 percent. "Mortgage rates have been relatively stable, hovering near record lows, for the past four weeks which is helping to spur new home construction," said Frank Nothaft, vice president and chief economist, Freddie Mac. "For instance, new construction on single-family houses rose to an annualized rate of 613,000 in January, the most since July 2008. In addition, single-family building permits were up to the highest issuance level since June 2008." The five-year Treasury-indexed hybrid adjustable-rate mortgage (ARM) averaged 2.64 percent this week with an average 0.5 point, the same as last week. A year ago, the five-year ARM averaged 2.80 percent. The one-year Treasury-indexed ARM averaged 2.65 percent this week with an average 0.4 point, up from last week when it averaged 2.61 percent. At this time last year, the one-year ARM averaged 2.73 percent.