LOS ANGELES – When Michael Bay began directing music videos, he scouted a modern house in Bel Air as a possible site to use as background for the hard rock band Aerosmith. “I was in my 20’s and I remember opening the door and saying, ‘Man, I’d love to own a house like this some day,’ ” he said.

Today, Mr. Bay, 39, owns that two-story, 10,000-square-foot, five-bedroom house, so high on a hill that he can see the Pacific Ocean and the city. “I liked the clean lines, and the scale of the house,” Mr. Bay said. “But the owners’ art was a little too colorful for me.”

That from the director responsible for frenetic, pyrotechnic machine-gun-paced action films like “Bad Boys,” “Armageddon” and “Pearl Harbor.”

Gym-trim and tall, with longish hair the color of wet sand, Mr. Bay seemed relaxed at his home one morning earlier this month, having only just put the final crash and bang into his film, “Bad Boys II,” which opens tomorrow. (Relaxed? He clarified: “This is me being tired.”)

He walked past the paper lanterns, candles and willow branches in his sisal-carpeted Japanese-inspired living room, opened the door to the pool, and greeted Mason, his 250-pound English mastiff. “Go get your toy,” Mr. Bay commanded, tossing a red ball into the pool. “Go swimming, go on, buddy. Jump!”

The dog — who has received no formal acting training, and yet, thanks to his close relationship with the director, appears in two pivotal scenes in “Bad Boys II” — looked balefully at Mr. Bay, looked at the ball, made some kind of mental calculation, and then heaved himself into the water.

Short of plowing his Ferrari 575 Maranello into the kitchen, this may be as close as Mr. Bay comes to staging action scenes at home. But a mastiff jumping into a swimming pool is barely a drip of condensation on a glass of iced tea compared with Mr. Bay’s trademark ultramacho films, which display enough firepower to, in the case of “Armageddon,” blow up an asteroid headed for earth. In the new movie, he sends a Humvee careering down a hillside in Cuba, leveling an entire shantytown; the characters are caught in a field of land mines, blow up a drug dealer’s $40 million retreat, destroy more than 20 cars in a chase scene, and, in another chase scene, run over cadavers falling out the back of a hearse.

Instead of creating a place that is flashy, loud and full of eye-popping colors, Mr. Bay, with the help of a friend’s mother, Merle Mullin, has made a subdued and serenely decorated home. His chef, Lisa Renta, said it feels “like a spa.”

Jerry Bruckheimer, the producer of all five of Mr. Bay’s films, said: “He gets so much adrenaline at work that when he gets home, he’s exhausted. The hyperspeedy way he works — they call it Bayos, as in chaos — is different than the way he is personally.”

When Mr. Bay bought the one-acre property four years ago for $5 million (he also has a home in Montecito, high above Santa Barbara), the owners’ art was gone, but the house had a dated, 1980’s feel. “It was old modern,” Mr. Bay said. “The floors were bleached wood or carpeted, the walls were white, and there was a sense of volume but not of contrast.”

He put in dark floors (some wood, some concrete), natural sisal instead of carpet, and did the walls in Italian plaster, which he painted in muted earth tones. “New modern is Asian and rock and a sense of nature,” he said. “It’s mixing up different woods and textures, and, to break up the monolithic feeling of the house, it’s using big dark Japanese pieces.”

Mr. Bay in short: big action, big dog, big Helmut Newton picture book, big furniture.

Mr. Bay demurs. “Believe it or not, with the scale of the rooms, if you had regular-size couches, they’d disappear,” he said.

On a tour of the house, Mr. Bay pointed out a work in progress, a fireplace in the den, and offered up a picture ripped from a magazine to show the look he was going for. “I read home décor magazines all the time,” said Mr. Bay, whose movie, “The Rock,” was about a plot to destroy San Francisco with nerve-gas-bearing rockets launched from Alcatraz. “It’s the way to stay hip and it helps me when I think of sets.”

Upstairs, he opened the door to a Dorian Gray room. “This is what the whole house used to look like,” he said. The room screams 80’s: beige wallpaper, beige wall-to-wall carpet and a beige bed. Who sleeps here? Mason, the mastiff. Extravagant as his films are, Mr. Bay is not one to redo a bedroom for a dog. (Grace, a second English mastiff, sleeps downstairs, “for security purposes,” he said.)

Mr. Bay sleeps in a soothing light-filled room. Silky white curtains flutter next to a minimalist daybed. This, more than any other room, seems like a movie set — although not from any of Mr. Bay’s movies. “Compared to the rest of the house, the starkness here is masculine,” he said. “But the curtains are definitely feminine, and so are the silly hearts on the bed.” He was referring to the heart-shape, red satin pillows filled with lavender on his large bed.

His eyes shifted sideways, as if he were embarrassed. “There’s always a problem with girlfriends who come over,” he said and then stopped.

“Well, I had a girlfriend a few years ago who brought over too much feminine stuff,” he said. “The girlfriend I have now is much more design-oriented. She wouldn’t want floral curtains.”

His girlfriend of the last several years, Lisa Dergan, 32, who announces scores on a Fox Sports cable channel, studied interior design at San Diego State University. She was then asked to do the interior decoration for the Chili’s restaurants in the West. (She had once been a waitress at Chili’s and had made an impression.) Ms. Dergan went on to become Playboy’s Miss July 1998.

Mr. Bay was raised in Westwood, a few miles down the hill, in a traditional colonial-style house. He responded to things visually from an early age, winning a national award for photography when he was a senior at Crossroads, a private school in Santa Monica. But he never considered himself part of the artsy crowd, which he defines as intellectuals who hang out at revival theaters.

He was not above throwing eggs at passing cars. “But the worst thing we’d do is throw a wet Nerf football at a car so the driver would think he’d hit an animal or something,” he said. “And the sound of screeching brakes!”

“It was terrible,” he said, hardly seeming to mean it.

He joined a fraternity at Wesleyan, where he majored in film and played baseball. He attended film school at Art Center in Pasadena, and then turned his soul over to commerce. His project for his graduate degree was a mock-Coke commercial, shot aboard the battleship Missouri with hundreds of student extras.

The rock videos followed that, and his explosive and visceral shooting style, as well as his offbeat sense of humor, won him jobs directing real commercials for Coke, Miller beer and milk. “When I started, commercials were done by old guys in their 50’s,” he said. “It was an old-boys’ network. We took a lot of work away from those people.”

He was 30 when he directed “Bad Boys,” a high-octane, irreverent cop-couple confection with Martin Lawrence and Will Smith. While the film had a budget of $23 million, it earned $140 million in theaters and that success was the first of his souped-up popcorn movies, which have very little character development but very muscular box office returns.

Having established himself, Mr. Bay may now qualify as a member of the old-boy network. But that term upsets him. “I still raise the bar by the way I shoot action and work the camera,” he said. “And if you are not on your game in this business, they spit you out so fast. It’s ruthless. Ruthless. I am on my game because they pay me to be on my game. And I deliver.” For the six months he was in Miami shooting “Bad Boys II,” which cost more than $100 million to make, he said, “I wasn’t even a consumer. I bought one polo shirt.”

Poor Mr. Bay. He has been criticized for having the sensibilities of an adolescent. “I make movies for teenage boys,” he said. “Oh, dear, what a crime.”

Mr. Bruckheimer points out that Mr. Bay has never made a movie that failed. Yet “Bad Boys II” is not going to expand his reputation. “I knew the movie was going to do nothing for my career,” Mr. Bay said. “And to tell the truth, shooting action bores me now. But the audience has grown to like what I do and expect visually stimulating excitement. Staying in that genre is me being safe.”

Maybe that explains the house.

Adrenaline junkies like Mr. Bay have discovered a legal way to block out hard-to-handle feelings, and charge $8 a pop for it. But even though he loves fast cars, lives in a $5 million house and dates a Miss July, he insists he does not live in the fast lane. “I’ve never gambled,” he said. “I’ve never sky-dived. I did get to fly in an F-16, but only for 15 minutes.”

His serious and well-thought-out house would seem to belie his wind-up-toy movies. Mr. Bay may now be ready to grow up creatively. If only he could figure out how.