When local resident Sara Nainzadeh was redesigning her apartment a few years back, she spent $25k to build this secret room behind a bookcase in her 3 bedroom apartment. See how it all works in this video from our friends at INSIDER.
The third bedroom did, in the end, become an office space. And a lounge to hang out with her friends. You just have to get there by pulling a book off a shelf. With the help of the company Creative Home Engineering, Nainzadeh got herself her secret room.