The measure would require referendum votes for changes in the power of the city's Historic Preservation Board or cuts in preservation regulations, The Miami Herald reported.
Miami Beach, on the site of a failed coconut plantation, was incorporated in 1915. Some buildings that have historic designations are less than 50 years old, including the Fontainebleau Hotel, designed by Morris Lapidus and dating from 1964.
Barbara Capitman, founder of the Miami Design Preservation League, won a historic designation for South Beach's Art Deco district in 1979 when hotels like the Fontainebleau and the Eden Roc, built in 1956, were still new. The district including the two hotels received its designation three years ago.
Historic status has been a winner for South Beach. But Mayor Matti Herrera Bower said she wanted to strengthen the rules because newer and younger residents did not remember the effort in the 1970s.
"As we move forward, you realize that there aren't that many people who fought the battle left," Bower said Monday, before the vote.