In a lengthy ceremony last night, the Cambridge Historical Commission rewarded 20 Cambridge buildings for recent renovations--including the Harvard Coop and the Fly Club, for recent renovation efforts.

Charles M. Sullivan, the historical commission's executive director, handed out the awards at the Third Annual Preservation Recognition Program at the Harvard-Epworth United Methodist Church. The ceremony honored efforts to recognize historic buildings.

"Part of our function is to promote historic preservation not only through regulations, but recognition as well," he said.

Although Mayor Francis H. Duehay '55 left early for a School Committee meeting, he made some brief remarks at the beginning of the ceremony.

"I wanted to be here to thank you for your efforts to conserve the historic heritage of the city of Cambridge," he said.

Two Harvard Square buildings were among the 18 honored.

The Harvard Cooperative Society, founded in 1872, built its current building in 1924 in the center of the Square. However, a huge awning covered the original facade, which Sullivan described as "an elegant, classical Georgian facade," in the early 1950s.

However, the Coop's recent renovations removed the awning and returned the building to its original state.

"The original entrance has been brought back in real first-class style," Sullivan said.

The original Fly Club building on Holyoke St. was constructed in 1896 by Herbert D. Hale, an architect affiliated with the club.

Although most of Mt. Auburn St. and Harvard maintained a brick facade, Hale designed a wood frame building.

In 1902, however, the Fly was renovated with a brick exterior, which resulted in severe structural difficulties and water damage this decade.

The renovation this fall, which was reviewed by a state historical society, garnered the preservation award.

"The building just gleams at this point," said Sally Zimmerman, another historical commission member.

The other buildings recognized at the ceremony ranged from small property owners who renovated their properties to the Lesley College and Cambridge Home's renovation projects.