The White House is valued at more than $US308 million dollars, making it the most expensive residence in the United States, a real estate research firm said Thursday.

It is still about $US23 million dollars less than its value a year ago, said in an indication that the White House has not been spared from the US home mortgage meltdown, the epicenter of the global financial crisis.

Using a formula that determines a home's current estimated worth based on public data and recent sales, Zillow valued the residence of the US president at $US308,058,000 dollars.

It 'would make this by far the most expensive residence in the United States,' the Seattle-based firm said in a statement ahead of president-elect Barack Obama's January 20 inauguration.

The Age