Rates on 30-year and 15-year mortgages fell this week, according to a Freddie Mac survey released Thursday.

Rates on 30-year, fixed-rate mortgages averaged 5.75 percent, down from 5.83 percent last week, Freddie Mac said in its weekly survey. The rate was the lowest on 30-year mortgages since the beginning of April.

Rates on 30-year mortgages hit a high this year of 6.34 percent the week of May 13. Rates slowly drifted downward as economic activity cooled in the late spring and early summer and inflation fears receded.

For 15-year fixed-rate mortgages, a popular option for refinancing, rates decreased this week to 5.13 percent, from 5.22 percent last week.

Rates on one-year adjustable rate mortgages averaged 4.03 percent, up from 4 percent last week.

The Federal Reserve is widely expected to increase short-term interest rates next week by one-quarter percentage point to 1.75 percent, which would mark its third rate increase this year.

Freddie Mac's chief economist, Frank Nothaft, said he did not see such an increase as "having a significant impact on long-term mortgage rates."

The nationwide averages for mortgage rates do not include add-on fees known as points. The 30-year and 15-year mortgages each carried a 0.8 point fee. One-year ARMs carried an average 0.7 point fee.

A year ago, rates on 30-year mortgages averaged 6.16 percent, with 15-year mortgages at 5.46 percent and one-year ARMs at 3.87 percent.

The Mortgage Bankers Association, meanwhile, said refinancing accounted for 43.2 percent of all home mortgage applications filed last week, up from 41.4 percent the previous week.

EVENTS . . . The National Building Museum at 401 F St. NW, Washington, holds its Festival of the Building Arts today from 10 a.m. to 4:30 p.m. Children and adults can build a brick wall, thatch a roof or climb aboard a concrete mixer. Admission is free; a $5 donation is suggested. For information, call 202-272-2448; Web site: www.nbm.org. . . . The Northern Virginia Association of Realtors plans to hold its annual Economic Summit on Wednesday from 8:30 until noon at George Mason University, Fairfax Campus, in the Johnson Center Cinema. Speakers are to discuss the local economy and its effect on the housing market. Admission is $49 for members and $59 for non-members. For information or to register, call 703-207-3200; Web site calendar: www.nvar.com.

PERSONNEL . . . Coldwell Banker Residential Brokerage named Alvin D. Tucker Sr. branch vice president of its Oxon Hill sales office.

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