E-Valuers are tested every week against property sales from the last six months. The results show that nationally E-Valuer consistently values properties within 10% of the actual selling price over 69% of the time, and within 20% of the selling price for over 93% of properties.
Internationally, being within 10% of the actual selling price approximately 65% of the time is considered to be very good, indicating that the performance of our E-Valuer is world class.
To help you understand the accuracy of your E-Valuer we provide a confidence level indicator, based on a Forecast Standard Deviation (FSD) calculated for each estimate. The FSD calculation is based on analysis of the comparable sales used by the E-Valuer to gauge how accurate the E-Valuer is likely to be.
The FSD represents the probability that an E-Valuer will fall within 68% (one standard deviation) of the actual market price. The lower the FSD the closer the estimated value is likely to be to the actual sales price. For example — if a property shows an FSD of 10%, this means there is a 68% probability that the actual market value will fall within ± 10% of E-Valuer's estimated value.
We also provide a visual confidence scale in relation to the FSD. When the confidence level is medium to high you can be more assured that the estimated value is accurate. If you see a low confidence level, it doesn't necessarily mean that the estimated value is inaccurate. Instead, it normally means that the property or area has some variances or unique attributes that make it difficult to find similar properties to compare it with. When this occurs we recommend you investigate the comparable sales displayed more carefully.
Some of the reasons why an E-Valuer might not be available or where the E-Valuer may be outside the value range include: