The reason golfer Tiger Woods’ ex-wife tore down the $12 million mansion she bought with their divorce settlement is so that she can slip into something slightly bigger than the original 18,000 square feet.

Through a lawyer, Elin Nordegren, 31, applied for permits to build a 21,300-square-foot place in the exclusive enclave of Seminole Landing in North Palm Beach, according to records.

The permit process is still ongoing, but Gossip Extra got an early peek at Nordegren’s plans for a three-story behemoth just feet from the Atlantic.

Total cost of the project: $3,447,612!

She can afford it, and then some: The Swedish former nanny made more than $100 million in the split.

Nordegren, who’s sharing custody of her two kids with Woods, had an architect design a new home that, like the old one, reminds observers of a European country home.

And the numbers indicate she’ll have plenty of space: a 1,102-square-foot exercise room; a 1,000 master bedroom; a 600-square-foot home-theater; and an 1,182-square-foot kitchen.

Hometown hero

Former ‘N Sync front man JC Chasez is credited for saving a toddler’s life during a freak incident in Miami Beach the other day.

Jewelry designer Netali Nissim tells Gossip Extra that she and her family were sitting on the beach in front of the Fontainebleau when a sleek helicopter flying close to the ocean caused a burst of wind that sent the family’s heavy beach umbrella soaring into the air.

When it landed, the contraption headed straight down toward Nissim’s 1-year-old daughter, Shirel.

That’s when Chasez, who was sitting with a gal pal near the Nissims, sprung up and shielded the little girl with his body. The umbrella bounced off his shoulder, and no one was hurt.

“Everything went so fast,” Netali Nissim said from her home in Chicago. “He was very humble about it. He said: ‘That’s the least I can do!’

“If he weren’t there, I’m pretty sure my baby would’ve been hurt.”

RADIO BRIEFS . . .

… WQAM-560 AM shock jock Sid Rosenberg returned to the airwaves Jan. 3 after a six-week suspension without pay. With the theme of Welcome Back Kotter playing in the background, Rosenberg talked about the suspension like it was a vacation. He discussed his losing weight in daily runs on the beach at high noon — but not a word about his attempt to plug a gambling website to which he owed $100,000-plus. ... Pressure, pressure! Y-100 jock Michael Yo has been given the nod to emcee a huge black-tie gala next Saturday at Donald Trump’s Mar-a-Lago in Palm Beach. Yo, who also is Chelsea Handler’s occasional sidekick on E!’s Chelsea Lately, will be working the 30th anniversary gala of the high-profile nonprofit Susan G. Komen For The Cure. Guests are set to include Gov. Rick Scott and Sen. Bill Nelson and, of course, The Donald. The dinner could end up raising $1 million-plus for breast cancer research . . .