Thoughts From Your Valuation Source

"Part of the reason home prices are declining is a fundamental deterioration in the housing stock," said Glenn Kelman, CEO of the online, discount broker Redfin. "During the boom, nine out of 10 houses for sale in many markets were in prime condition. Now, for every 10 houses, at least three are dogs."

Most of these mutts are foreclosed properties that have been permitted to fall into disrepair by lenders overwhelmed with thousands of vacant homes. If these houses sell at all, they're going for bargain basement prices that are hurting home values throughout the neighborhood.

"I've never seen so many houses in this condition before," said Ray Anderson of Buyer's Advantage Real Estate in Auburn Calif., near Sacramento. "And I've been in the business 20 years. I've seen bank-owned properties in the past. They were never like this."

Distressed properties usually sell for discounts of 10% to 40% below comparable, well-maintained homes, according to Tom Inserra, executive vice president for Zaio, an appraisal company that is creating a national database of home values.

Richard Smith, CEO of Realogy, the parent company for Coldwell Banker, Century 21 and Sotheby's International Realty, estimates that homes that are not bank-owned have actually only seen price declines in the low single digits over the past 12 months. That's compared with the 15% price drop recorded by the S&P/Case-Shiller Index for all homes over the same period.

While the subprime crisis is still in full swing it will take time to see what kind of effect this will have overall.