Zillow is a popular Internet marketer that provides "z-estimates" that purport to calculate the value of every residence in the United States. Zillow tries to reach this goal this feat by using a complicated logarithm which crossreferences factors which alter real estate values, but here's a story I have heard from real estate sellers in Northern Virginia:

Our home was recently appraised for 650K. Zillow estimates the value at 521K. The estimate makes us one of the lowest priced homes in the subdivision. We have all upgrades in our home and it is the largest of the homes that were originally built in this subdivision. It was appraised at 750K before 2009. Our home has a basement. Neighbors do not have basement on one side and you appraised higher. Really? -- James E. - Fort Hunt

If you research the Internet for the phrase "Can I trust Zillow?" or "Can I trust Z-Estimates" you'll find many posts by angry property owners and skeptical real estate purchasers who have discovered the hard way just out inaccurate Zillow's pricing can be. Many people in North Hill report that Zillow's valuations have a margin of error of around 20%. Even if we assume the margin of error is only 10%, in Northern Virginia that means a "z-estimate" is only within $50,000 of the actual sales value. If the margin of error is an impressive 5% that means that a z-estimate is only within $25,000 of the asking price.

Yet Zillow (for now) remains popular with some buyers and sellers. Real estate sellers and real estate shoppers should know that there is not a single community in North Hill where either a bank or tax collector uses Internet for tax assessment or appraisals. Our expert advice is to take estimates from any computer at arm’s length. Putting too much trust into a computer can cause a great deal of disappointment.

Call one of our agents today for a free comparative market analysis of your property's worth. We promise that a website won't set the ideal price. Instead, your friendly neighborhood Nesbitt Realty Realtor will measure the complicated variables which make up your real estate's sales value.