Did already expensive homes get even more expensive? How much higher can prices go for these kinds of home? Read on below to learn more about this topic.

The big housing boom that the nation experienced over the last five years, especially from the third quarter of 2001 through the third quarter of 2006, has not only perked the overall housing prices in the country, but also created a significant rise in the prices of America's richest Zip codes.

The Standard & Poor's Case-Shiller Home Price Index registered a five year increase of 63.7 % in home prices, for the nation in totality, according to Fiserv Lending Solutions, that supplies data and software to lenders. Meanwhile, the Zip codes that had a median sales price of $750,000 and more, showed an increase of 79.5 %.

Let us take a look at the housing prices in the richest Zip codes of America and the changes that have happened over time. Given below are the top 10 richest Zip codes in the U.S. where median property prices rose to the greatest extent since 2001. The median property values featured in the top ten are listed from the 2nd quarter of 2006. The percentage of appreciation is based on a comparison of single-family home prices over the last 5 years - that is, between the 3rd quarter of 2001 and the 3rd quarter of 2006.

1. Greenwich, Connecticut: Zip code 06831, Median Price (2006:Q2): $2,983,000, five year appreciate rate: 49.3 percent. Bridgeport-Stamford-Norwalk metro area.

2. Newport Beach, California: Zip code 92661, Median Price: $2,500,000, five year appreciate rate: 132.2 percent. Santa Ana-Anaheim-Irvine metro area.

3. Paradise Valley, Arizona: Zip code 85253, Median Price: $1,850,000, five year appreciate rate: 100.4 percent. Phoenix-Mesa-Scottsdale metro area.

4. Avalon, New Jersey: Zip code 08202, Median Price: $1,687,500, five year appreciate rate: 125.7 percent. Ocean City metro area.

5. Cambridge, Massachusetts: Zip code 02138, Median Price: $1,395,500, five year appreciate rate: 22.4 percent. Cambridge-Newton-Framingham metro area.

6. Glen Head, New York: Zip code 11545, Median Price: $1,150,000, five year appreciate rate: 67.2 percent. Nassau-Suffolk metro area.

7. Islamorada, Florida: Zip code 33036: Median Price: $1,150,000, five year appreciate rate: 204.3 percent. Key West-Marathon metro area.

8. Chevy Chase, Maryland: Zip code 20815, Median Price: $1,043,000, five year appreciate rate: 94.8 percent. Bethesda-Gaithersburg-Frederick metro area.

9. Hinsdale, Illinois: Zip code 60521, Median Price: $950,000, five year appreciate rate: 48.4 percent. Chicago-Naperville-Joliet metro area.

10. Bellevue, Washington: Zip code 98004, Median Price: $950,000, five year appreciate rate: 83.9 percent. Seattle-Bellevue-Everett metro area.

Source: BusinessWeek Online, Peter Coy and Maya Roney (04/02/07)