Freddie Mac reports a decline in the 30-year fixed mortgage rate to 5.47 percent during the week ended Dec. 11 from 5.53 percent last week and 6.11 percent a year ago. 

Some lenders are locking in even lower rates as they build on momentum started when the Federal Reserve announced plans last month to purchase a substantial number of mortgage-backed securities. HSH Associates and Inside Mortgage Finance are reporting interest on 30-year fixed loans at 5.33 percent and 5.09 percent, respectively. 

Freddie Mac chief economist Frank Nothaft says mortgage rates also were driven downward by the recession and rising unemployment.