LOS ANGELES — On a sunny January 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.

He was less focused on his semiprivate panorama of the city, with the landmark Hollywood sign seemingly close enough for him to grab in one hand, than on the unused rooftop around him.

Though Mr. Corden, 36, does not start his show here 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?