– On a sunny afternoon, James Corden stood on the roof of CBS Television City, the boxy building where he will take over as host of the network’s “Late Late Show,” and surveyed his new domain.

Although Corden, 36, does not start his show until March 23, he was excitedly describing a hypothetical plan to have a camera track the path from the “Late Late Show” studio below — presently as barren and yawning as a high school gymnasium — to this outside area where some of-the-moment rock band could perform for his program.

“This is ours,” he said in his resonant British accent. “All this is ours.”

But will CBS actually let him do this?

“Well,” he replied with a chuckle, “I’m not entirely sure if they’ll let us do anything.”

Four months earlier, CBS revealed that it had hired Corden, a bubbly, burly British actor and comedian not widely known in America, to take over the show from Craig Ferguson, who had made it his perch for stream-of-conscious monologues and laid-back interviews for nearly 10 years.

Now that Corden has the job, he has a few weeks to wrestle with the existential question of just what the job is: to summon the irrepressible energy he has channeled as a British TV host and Tony Award-winning Broadway star; to set aside the question of whether U.S. viewers know who he is (“I hope it doesn’t matter,” he said, “because no one does”), and to determine what to create, keep or throw away in an hourlong program where he is inheriting little more than its title.

Speaking later in his office, furnished with a basic desk and couch and a box of diapers for his infant daughter, Corden said: “When you get a job like this, your first thought is, ‘Oh, let’s rip up the rule book — let’s do the whole show in a white box!’”

But he quickly realized, he said, “No one wants to be the arrogant British guy who isn’t paying homage to the institution.”

Presented with the deceptively limited format of a late-night talk show and charged with attracting a youthful viewership in an oversaturated landscape, Corden asked: “How do we bring an audience who are, in many ways, lethargic and apathetic about watching television when it’s on? How do we show them that this is a show worth staying up for — that is worth closing their laptops for?”

Beyond his door were empty offices and desks, waiting to be populated with the staff responsible for helping answer these questions. So far he has hired five writers — late-night veterans David Javerbaum (“The Daily Show”) and Mike Gibbons (“Tosh.0”) and comedians Sean O’Connor, James Davis and Ian Karmel. They have started brainstorming ideas for a program that so far has no form or structure.

But so far, it is Corden who is primarily driving this train, peppering his colleagues with mission statements about what his show should or should not be.

“We’re on at 12:30 [11:30 p.m. Twin Cities time], so we’re always going to be pushing up against the constraints of that,” he said. “We have to turn that into a positive for our show. We have to be like Stephen Colbert’s younger brother with ADHD.”