Inspired by the Case-Shiller Index, I decided to make my own index of prices for various Northern Virginia neighborhoods. For those unfamiliar with the Case-Shiller index, unlike the NAR and other data on home prices which use parametric statistics, usually the median, to gauge home prices, the Case-Shiller index looks at repeat sales. Parametric statistics are vulnerable to changes in the underlying distribution (e.g. what if large houses become unfashionable).

For my initial foray, I decided to examine the prices of 4BR (four bedroom) SFH (single family detached homes) with a basement with between 2000-2500 square feet. Note that the square footage excludes the basement. If you include the basements, then square footage would range from roughly 3000-3750 sq ft.

I chose this size of home because it appears to be a popular size throughout the region, making apples-to-apples comparisons easier among neighborhoods. In older neighborhoods, these might be considered larger houses, whereas in newer neighborhoods these might be on the smaller side. Also, these tend to be colonial-style homes: no ranches or split-levels.

I originally chose to sample more neighborhoods (e.g. McLean and Manassas), but the task of finding comps (square footage, taxes, etc.) is a bit tedious, and I ran out of steam. All data is from the Loudoun and Fairfax county tax databases.

In the future I'd like to add a second size bracket (3000-3500 sq ft) and include Manassas and McLean in the mix.



• The 3rd graph, price percentage from peak, does a nice job of illustrating the cascading fall of prices as it works from the outlying areas inward.

• The 2nd graph, percentage of 1998 prices, illustrates the huge run-up in the region.

• The 3rd graph, in case anyone cares, is of the mean values of the houses sampled from the difference areas.