The 41-year-old Spanx founder, who transformed $5,000 of her own money into a $1 billion shape-wear empire, didn't hold back when it came to designing her new solar-powered Atlanta home.
"It started as a minor renovation, and I basically built a house inside of a house," says Blakely, who spent two years infusing the 10,000-sq.-ft. home with her "eclectic" style that blends bold patterns (check out that zebra print rug!) and strokes of whimsy.
A giant gumball machine greets visitors in the foyer, and an indoor-outdoor vibe gives the home a "tree fort" feel, says Blakely, whom in March Forbes named the world's youngest self-made female billionaire.
Son Lazer, 3, enjoys a dream playroom, and fitness-focused husband Jesse Itzler, 43, gets spa-quality steam and sauna rooms.
"He likes to do steam and sauna after a workout to get rid of the toxins," she says. "I'm like, 'Honey, what are you sweating out? Coconut water?' I need to be in there to sweat out Tex-Mex food!"
For exclusive photos of Sara Blakely's Atlanta home – and how she juggles motherhood, marriage and moguldom – pick up this week's issue of PEOPLE, on newsstands Friday