The actresses met while shooting their upcoming buddy cop comedy and instantly connected, said the film’s director, Paul Feig.

"They were thick as thieves almost from the start,” Feig said Sunday on the red carpet at the film’s Ziegfield Theatre premiere. “It was almost to the point where I was like 'Hey, can I get in there?'"

Bullock, 48, and McCarthy, 42, quickly discovered they had kids around the same age and shared the same sense of humor. But they also had something more unusual in common: An obsession with fixing up their homes.

"There’s very few people that have a home renovation sickness in this business," said Bullock, dressed in a form-fitting black leather dress with revealing cutouts. "I think maybe two. She and I have to be the two."

The fixation runs deep, McCarthy explained.

"Hours are spent, like, 'Did you see this wood?' There’s nobody else who wants to talk to me about this stuff in such depth."

On the red carpet, the pair’s friendship was evident as they posed playfully for the cameras, McCarthy pretending to choke Bullock.

It’s almost as if "they knew each other from another life," costar Demian Bichir said, observing the antics. "They’re like sisters. They’re adorable together."

In "The Heat," Bullock plays a straight-laced FBI agent who is forced to team up with McCarthy’s outspoken Boston cop. The movie hits theaters Friday against "White House Down,"the big-budget Channing Tatum-Jamie Foxx action flick — but "The Heat" is primed to have a stronger opening weekend than the special effects-laden thriller.

Informed of that news, Feig seemed pleasantly surprised.

"Is it really? I mean — oh, well, that’s too bad for them," he said with a smile. "I hope it’s a wakeup call to everyone in Hollywood that we need to put more funny ladies in movies. We’re  the only studio film this summer with women in the lead roles — so let’s change that."