Can a new occupant ever make a mark on such a grand building as the White House, with all its history and heritage? Rome Hartman reflects on a few past presidents and their differing styles

Physically, the White House never seems to change. I've been going there for more than 20 years, off and on, and I'm always struck by the constancy of the setting. The formal areas are quite grand, of course, and meticulously maintained.

The White House has a permanent staff of conservators, and there are always a few on hand during set-up for an interview. They're the only people who are permitted to touch or move any of the furniture or artwork in any of these rooms, and watching them work always reminds me that while presidents come and go, the White House and its contents belong to the people of America.

Of course the atmosphere and feel of the place do change, a lot, depending on who's sitting in the Oval Office. I first covered the White House during Ronald Reagan's presidency, as a young producer for CBS News, and I remember being struck at the time by the formality of the place, and by a sense that it operated at quite a slow pace (perhaps I was just impatient).

When George HW Bush took over from Reagan, the atmosphere changed overnight. It was as if the pulse rate jumped by about 15 beats per minute, even as the sense of focus diminished a bit. Later, Bill Clinton's White House had an even less formal feel, and if an interview was set for 1pm, you wouldn't be at all surprised if it actually began at 2pm. George W Bush, on the other hand, has a well-deserved reputation for punctuality and rigour; for wanting events to happen just when they've been scheduled.

By this time next year, there will be a different feel to the place? a different occupant, atmosphere, and pace. But that staff of careful conservators will be the same.

Rome Hartman is Executive Producer, BBC World News America. This column is taken from his BBC blog about US politics and news