Average fixed mortgage rates moved just slightly lower following three consecutive weeks of increases, according to Freddie Mac.

The 30-year fixed-rate mortgage averaged 3.84% with an average 0.7 point for the week ending May 21, 2015, down from last week when it averaged 3.85%. A year ago at this time, the 30-year FRM averaged 4.14%. 

"Mortgage rates were little changed this week amid positive housing news. Housing starts surged 20.2% to a seasonally adjusted pace of 1.14 million units in April, the highest level since 2007,” said Len Kiefer, deputy chief economist, Freddie Mac. “As homebuying season moves into full swing, homebuilders remain positive about home sales in the near future. Although the NAHB housing market index slipped 2 points to 54 in May it is still above 50, indicating that on balance builders remain optimistic about housing markets." 

The 15-year FRM this week averaged 3.05% with an average 0.6 point, down from last week when it averaged 3.07%. A year ago at this time, the 15-year FRM averaged 3.25%. 

The 5-year Treasury-indexed hybrid adjustable-rate mortgage averaged 2.88% this week with an average 0.5 point, down from last week when it averaged 2.89%. A year ago, the 5-year ARM averaged 2.96%. 

The 1-year Treasury-indexed ARM averaged 2.51% this week with an average 0.4 point, up from last week when it averaged 2.48%. At this time last year, the 1-year ARM averaged 2.43%.