The developer of a 25-unit project in Bay Harbor Islands is taking a sledgehammer to walls dividing two units at the condo, creating a full-floor penthouse to meet unexpectedly strong demand for upscale dwellings with more than 3,000 square feet, a sales director said Friday.

The demand for larger apartments in the small village northwest of Miami Beach is catching developers by surprise, prompting some builders to look more closely at plans for future projects.

Dora Puig, the director of sales for the 25-unit Riva Bay Harbor project at 9400 W. Bay Harbor Drive, said the two penthouse units in the building were among the first to sell, an unusual dynamic for Miami’s real estate market. Interest has not abated since then, she said.

“It was the exact opposite of what I was expecting,” Puig told the DBR Friday, explaining that after the building’s two largest units were snapped up “we got a lot of calls where people are saying ‘Do you have a penthouse?’ and then we’d say, ‘No,’ and then they’d hang up.”

“I think more people are settling here, and we’re in a more end-driven market than during the last boom, so clients are demanding more space,” she added.

That dynamic could help the developer’s bottom line.

In the Riva Bay Harbor, Puig said the 10 units sold so far have averaged $527 per square foot. But larger units sell at a premium. The two penthouses sold for $605 and $617 per square foot, respectively. According to real estate website Trulia, the average price per square foot for Bay Harbor Islands is $223.

There are 13 projects either planned or proposed for Bay Harbor Islands, according to Miami construction database

Puig told the DBR the developer of one of those projects, whom she did not name, was in her sales center last week and “because of what we’re doing, he’s only doing large units now.”