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.