We are all trying to get a handle on the real effect of the real estate market on our pastures. Every year Forbes commissions Altos Research, which is a company located in Mountain View, that tracks the real estate market and ranks the most expensive zip codes. The list is a snapshot of one day in time, so a single sale can skew the results. Nonetheless, the information is interesting view of the upper end real estate market. Altos Research studies over 15,000 zip codes, which amounts to about 90% of all real-estate transactions. http://www.altosresearch.com/ The home prices were determined by asking price for single family and multiple family homes on August 14, 2009.

Home prices in these expensive enclaves experienced a 7% average drop in asking price, although in many places, prices fell even more. ZIP Code 07620 in Alpine, N.J. which headed the list had a median asking price of $4.14 million with an inventory of 48 homes. However, homes were on the market an average of 250 days and prices there fell 23% over the past year.

While last year, California accounted for 96% of the 50 most luxury ZIP codes, this year it was less than 50%. Significantly, 83% of those California ZIP codes on the list posted prices that had declined or stayed the same.

Atherton ZIP 94027 ranked number 2 on the list with a median home price of $4,139,041 and an inventory of 49 houses. Houses stayed on the market an average of 133 days. Woodside ZIP 94062 ranked 35th with median home price of $2,424,031 and an inventory of 56 homes with an average time on the market of 177 days on the market. Nonetheless, this represents a gain of 3%.

Here are the 47 California ZIP codes which made the list:

 See the entire list here.

Many commentators expect further declines before luxury home prices hit bottom. Buyers are waiting for prices to fall even further. There is a lack of credit at the top end of the market. So, it is good to know that Woodside’s market, at least by this measure, seems fairly stable.