In South Florida’s suddenly resurrected real estate market, Miami Beach has plenty to offer buyers in search of a dream home.

Stocked with miles of bayfront land and picturesque waterways, the Million Dollar Sandbar boasts scores of pricey waterfront properties. And, for better or worse, many lots come standard with pre-WWII homes designed by some of Miami’s most famous early architects.

To some buyers, these homes are collectors’ items to be restored. To others, their presence is increasingly incidental and hopefully temporary.

In the past year, city planners say, 20 such houses have been approved for demolition in Miami Beach as buyers and owners choose not to laboriously restore or renovate and expand what exists but instead construct custom, modern homes. Compare that to just 13 the previous five years.

The trend has been called an “epidemic” by the city’s preservation-minded mayor. And it has caught the attention of activists, who this past week announced that they will begin scouring neighborhoods outside historic districts to protect notable homes from being demolished — even if it means battling couples and families.

“We hadn’t considered that owners would want to demolish such important structures, or fail to see their merit,” said Mike Kinerk, a leading member of the Miami Design Preservation League. “We will be moving to designate all important houses in the city.”

The new battle between preservation and property rights officially began Wednesday when Kinerk signed an application to designate an iconic whitewashed house on the southeast corner of super-exclusive Star Island a protected landmark in order to keep it from being torn down by Leonard Hochstein and his wife, Lisa Hochstein, a cast member of Bravo’s Real Housewives of Miami.

The 1925 home, designed by Walter DeGarmo, who designed some of South Florida’s most historic homes, is to be replaced by a 20,000-square-foot Neo-Classical estate. The proposal has evoked a strong reaction from critics, including the league’s chairman, Charles Urstadt, who called the plans “immoral” during a public hearing.

The Hochsteins have taken the criticism personally. In an interview Thursday, Leonard Hochstein called the attempt to designate his home historic a “despicable” publicity stunt. He said the long but thin home is beyond salvageable, citing electrical fires, structural flaws, a foundation that sits below a federal flood plain, an illegal third-floor addition and plumbing that doesn’t extend above the first floor.

“I’m not trying to make this home a museum,” he said. “I’m trying to make a home for my family.”

He is doing so within the confines of Miami Beach’s laws.

About a dozen years ago, the last time residential redevelopment outside the city’s protected historic districts became a hot political issue, the Miami Beach commission passed a law intended to maintain flexibility for property owners, but also encourage them to renovate older homes. They drew a line in the sand at the year 1942, and required that any proposal to raze “architecturally significant” homes built before that date receive approval from the city’s Design Review Board.

While proposals for large replacement homes require proof that there is “good cause” to demolish an existing, pre-1942 house, tearing down such homes often requires little more than approval for a new design unless the home is designated historic. And many homeowners have taken advantage this year, often building bigger houses on prime property.