The richest 1% of New York City residents are living in multimillion-dollar Frankenmansions

When an apartment or penthouse isn't big enough for wealthy New Yorkers, they get creative.

In recent years, several have combined multiple townhouses or building floors to create supersized homes - or Frankenmansions, as New York magazine's S. Jhoanna Robledo calls them.

To construct these Frankenmansions, some prospective buyers purchase multiple buildings at once, while others approach their neighbors to offer multimillion-dollar buyouts. (In either scenario, they need the city's approval before combining properties.)

Check out these 12 Manhattan Frankenmansions owned by big names - including Madonna and Sarah Jessica Parker - outlined below in red.