Not even the nation’s most recognized and iconic home can escape the deterioration that typifies today’s real estate landscape. The value of the White House fell 5.1 percent last year, according to the online real estate marketplace Zillow.com.

In January 2009, the company put the value of the White House at $308 million, based on the home’s physical attributes, historical value, and housing performance in the local Washington, D.C. market. But by January 2010, Zillow said the property had lost $15.6 million in value, putting the worth of the 132-room mansion at $292.5 million.

But Zillow says just like most homes across the United States, the White House’s decline in value over the past year was not as dramatic as it was the previous year. From January 2008 to January 2009, the company estimates the White House lost almost $24 million in value, or 7.2 percent.

According to Zillow, it’s a trend that’s playing out over much of the country. Based on the most recent data from the company, residential property values in the United States had fallen 5 percent year over year during the first 11 months of last year. Of course continuing declines are not what the industry is looking for right now, but that’s an improvement over how far Zillow’s national index fell during the previous 12 months – 11.9 percent.

In the Washington D.C. metro area, Zillow’s home value index fell 3.6 percent from November 2008 to November 2009. The company says that showed marked stabilization from the previous year, when it plummeted 15.6 percent.

Built from 1792 to 1800, on the design of an Irish architect, the White House totals 55,000 square feet and sits on 18 acres. It has 16 bedrooms, 35 bathrooms, three kitchens, and an underground bunker.