Automated property valuations

Are they reliable or just a waste of money?
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03.Case study

$140,000 difference

Husband and wifeAs part of the research for this article, Rachel and Paul, who were preparing to bid for a Sydney house at auction, bought property reports from four websites. They also arranged an independent valuation.

While not an estimate of which websites would be most accurate in a large sample, the exercise did prove that there are risks in relying on a computer-generated valuation.

  • The online estimates obtained for the same three-bedroom house differed by over $110,000 — ranging from $548,000 to $662,661.
  • The least accurate website was over $140,000 off the eventual sale price.
  • Some websites gave ranges so wide that they were of little use: for example, $543,000 to $782,000, or $484,800 to $706,000.
  • The licensed valuer was somewhere in between, putting a price of $630,000 on the property. (See the table below for more details.)

With such wide differences, the couple felt they couldn’t rely on the reports, and they weren’t sure which to believe. They eventually used the reports plus information from the selling agent to derive their own valuation.

"Our own estimate was based on previous sales in the area and the price estimation in the Residex report, which seemed the most comprehensive," Rachel says. "We added $25,000 for improvements that had been made since the property’s last sale, so we reckoned its market value was about $621,000. That was pretty close to the licensed valuation report of $630,000."

However, the price the property fetched at auction — $690,000 — exceeded everyone’s expectations. "The unknown factor is what someone else is prepared to pay," says Rachel. "The highest bidder might have been looking for two years and be willing to pay above market value, or might just have loads of money."

Although all the automated reports undervalued the property relative to its sale price, Rachel still thinks some are worthwhile for buyers.

"$50 is a small price to pay to be informed about the market," she says. "But some reports are better than others. The least useful ones were those that gave little information about comparable sales in the area or the property’s historical sale prices. The reports helped up to a point — but they don't take into account things like recent renovations, and the prices are really only a guide."

Table: e-Valuations compared

Internet estimations and valution for Sydney property, sold for $690,000 at auction two weeks later.
Company name Australian Property Monitors Residex RP Data Licensed valuer
Report name
Property Report
Individual Property Report
Property Explorer Report
RP Estimate
Certificate of valuation
Report price ($)
How is the estimate described?
Market price estimate
Best estimate or estimated value
Initial estimate
Unassisted valuation result / estimated value
Current market valuation
Range quoted ($)
Not given
496,415 to 606,729
484,800 to 706,000
543,158 to 782,163
Not given
Valuation or estimate ($)
Difference from licensed valuation ($)
Difference from licensed valuation (%)
Difference from sale price ($)
Difference from sale price (%)
Number of pages in report
Suburb median ($)
Not given
Not given

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