Mortgage rates set a new record lows in two weekly surveys for the seventh consecutive week. The Freddie Mac survey put the average rate for a 30-year fixed-rate mortgage (FRM) at 4.49% with an average 0.7 origination point for the week ending Aug. 5, down from last week’s average of 4.54% and a year ago, when the average was 5.22%. It’s a new record low for the survey, which began in 1971. The Bankrate survey of large banks and thrifts put the average rate for a 30-year FRM at 4.66% with a 0.42 origination point, down from last week’s average of 4.71% and a new record low for the nearly 25-year-old survey. Vice president and chief economist of Freddie Mac, Frank Nothaft, suggested GDP growth was the cause of record low mortgage rates. “Annual revisions cut the cumulative GDP growth in half over the past three years ending in the first quarter of 2010 from 1.4 percent to 0.6 percent,” he said. “This reduces inflationary pressures and allows longer-term rates room to ease.” A new addition to the Bankrate survey was a benchmark rate for 30-year jumbo FRMs, which averaged 5.34%, a record low reached this week, down from 5.43%. Freddie said the average rate for a 15-year FRM averaged 3.95% with an average 0.7 point, down from last week’s average of 4% and a year ago, when the average was 4.63%. The average is a new low for the 15-year survey, which began in 1991. Bankrate put the average rate for a 15-year FRM at 4.11%, down from last week’s average of 4.17%, as a nearly 25-year record low for the survey. Freddie said the five-year Treasury-indexed hybrid adjustable-rate mortgage (ARM) averaged 3.63% with an average 0.7 point this week, down from last week when it averaged 3.76%. A year ago, the five-year ARM averaged 4.73%. Bankrate said the five-year ARM averaged 3.95%, down fro mlast week’s average of 4.07%. The one-year Treasury-indexed ARM averaged 3.55% with an average 0.7 point this week, down from last week when it averaged 3.64%. At this time last year, the 1-year ARM averaged 4.78%. Write to Christine Ricciardi.