Rates on 30-year and 15-year mortgages fell this week to their lowest levels in six months, Freddie Mac said Thursday.

Rates on 30-year fixed-rate mortgages averaged 5.69 percent for the week ended Oct. 21, down from 5.74 percent last week, according to Freddie Mac's weekly nationwide survey.

Rates on 30-year mortgages hit a high this year of 6.34 percent the week of May 13. Then during the late spring and early summer, rates slowly drifted downward as economic activity cooled, easing fears about inflation. However, since late August, rates have been going up and down in a seesaw pattern as markets have responded to a variety of mixed signals on economic growth.

For 15-year fixed-rate mortgages, often used for refinancing, rates dropped this week to 5.07 percent, from 5.14 percent last week.

Rates this week for 30-year and 15-year mortgages were the lowest since the beginning of April, when they averaged 5.52 percent and 4.84 percent, respectively.

For one-year adjustable rate mortgages, however, rates edged up this week to 4.02 percent, from 4.01 percent last week.

The nationwide averages for mortgage rates do not include add-on fees known as points. Thirty-year and one-year ARMs each carried a 0.7-point fee. Fifteen-year mortgages had a 0.6-point fee.

A year ago, rates on 30-year mortgages averaged 6.05 percent, with 15-year mortgages at 5.36 percent and one-year ARMs at 3.79 percent.

PERSONNEL . . . The Golden Triangle Business Improvement District has named the executive committee members of its board of directors for fiscal 2005 and 2006: President Kathy Knizner, vice president of commercial properties for Mark Winkler Co.; Vice President Carlton Diehl, vice president of management services for Charles E. Smith Commercial Realty; Treasurer Robert Thompson, regional director for Manulife Financial; and Secretary Howard Riker, vice president for Hines.

EVENTS . . . The D.C. Preservation League plans a tour of rowhouses today, beginning at 1 p.m. with a lecture and slide presentation on rowhouse styles from the late 18th century to today by preservationist Sally Berk. Afterward, Shaw resident and Advisory Neighborhood Commissioner Alex Padro is to lead a walking tour of the neighborhood, including interior views of recent renovations. Participants are to meet at 1426 9th St. NW. Admission is $15; reservation required. Call 202-783-5144 for details. . . . Chris Luebkeman, director of Global Foresight and Innovation at the London-based engineering firm Arup, is to discuss the future of architectural design from 6:30 to 8 p.m. Wednesday at the National Building Museum, 401 F St. NW, Washington. Admission is $17; registration required. For information, call 202-272-2448; Web site: www.nbm.org.

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