How Much Is My House Worth - The Evidence Behind the Number and How to Demand It

The gap between the lowest and highest appraisal on the same property is rarely small. Thirty thousand dollars. Fifty thousand. Sometimes more. And all three agents, when asked to explain their number, can point to comparable sales and adjustments that make their conclusion sound defensible. Which it often is.

The confusion is understandable. Every agent has access to the same comparable sales data. If the data is the same, why are the conclusions different? Because appraisal is not a mathematical process. It is an interpretive one. The same evidence, in different hands, produces different conclusions - and most of them can be legitimate.

Why the Same Data Produces Different Numbers

Property appraisal starts with comparable sales - recent transactions of similar properties in the same area. Every agent in Australia uses the same publicly available data. The divergence begins not in the data but in what each agent does with it.

The problem is that no two properties are identical. A four bedroom house that sold three months ago on the next street is comparable - but it may have a larger block, a newer kitchen, a different aspect, or a better street position than the property being appraised. Each difference requires an adjustment, and adjustments are judgment calls.

Agent A adjusts down $15,000 for the comparable the superior kitchen of the comparable property. Agent B adjusts down $25,000 for the same feature. Agent C decides the subject the north-facing aspect of the subject property outweighs the kitchen difference and adjusts up $5,000. Same comparable sale. Three adjustments. Three conclusions. All defensible.

Multiply that across five or six comparable sales, each requiring multiple adjustments, and the range of legitimate conclusions widens considerably. By the time three experienced agents have worked through the same data set independently, a $40,000 to $60,000 spread in their conclusions is not a sign that someone is wrong. It is a sign that the interpretation process genuinely produces different outcomes in different hands.

The comparable sales are the evidence. The appraisal is the argument built from that evidence. Different arguments, built from the same evidence, can reach different conclusions - and in property, all of them can be legitimate.

What Every Agent Is Actually Trying to Produce

The divergence in appraisal numbers is not only about interpretation. It is also about motivation. Not every agent approaching an appraisal is trying to answer the same question.

The first motivation is evidence - an agent genuinely attempting to identify the most likely sale price based on comparable sales and current market conditions. This agent selects the most relevant comparables, applies considered adjustments, and arrives at a number they are prepared to defend with specifics. Their appraisal may not be the highest of the three. It is the most useful.

The second type of appraisal is strategic. The agent has formed a view of the the property value and is presenting a price position that reflects their campaign recommendation rather than a direct read of the comparable sales. A lower list price to attract more buyers. A higher price to test buyer appetite. The strategy can be sound - but the vendor who does not recognise it as a strategy rather than a valuation cannot evaluate it properly.

The third motivation is listing acquisition. Some agents quote high to win the listing. The logic is straightforward: a vendor who receives three appraisals will often instinctively favour the highest because it confirms what they hope their property is worth. The agent who quotes highest wins the listing. After a few weeks on the market with no suitable offers, the agent begins the conversation about price adjustment. The vendor, already committed, adjusts.

This practice is common enough that it has a name in the industry. It is called buying the listing. It is not illegal. It is not uncommon. And it is the reason that the highest appraisal of the three is frequently the least reliable.

The Test That Separates Evidence From Flattery

The number alone does not reveal whether an appraisal is defensible. The evidence and reasoning behind it do. Two appraisals at the same figure can have completely different levels of analytical rigour supporting them.

A defensible appraisal is specific. The agent can name the comparable sales, explain why they selected them, articulate the adjustments made and the reasoning behind each one, and identify what conditions would need to change for their number to be wrong. That level of specificity is the mark of an evidence-based appraisal rather than a pitch.

A flattering appraisal tends to come with generalities. The market is strong. Your property presents beautifully. Buyers are looking for exactly this. The comparable sales are referenced but not interrogated. The adjustments, if mentioned at all, are vague. The number feels like a conclusion in search of evidence rather than evidence in search of a conclusion.

Ask the question directly: which three comparable sales most influenced your appraisal and what adjustments did you make for each one? The answer is the test. An agent who responds with specific sales, specific adjustments, and specific reasoning is working from evidence. An agent who redirects to market conditions or general enthusiasm is not.

The second test is asking each agent what would need to happen for their number to be wrong. An agent who has genuinely interrogated the evidence knows the assumptions their appraisal rests on and can articulate them. An agent who cannot answer that question has not built an appraisal - they have built a pitch.

The Right Way to Resolve Conflicting Property Appraisals

The instinct to split the difference between conflicting appraisals is understandable but unhelpful. The average of three interpretations is not more accurate than any one of them. It is simply the average. Accuracy comes from evaluating the evidence behind each number, not from finding the midpoint between them.

The productive response to conflicting appraisals is to return to the comparable sales. Ask each agent for the specific sales they relied on and compare the lists. Where the lists overlap, the divergence is in the adjustments - examine those. Where the lists diverge, the disagreement about what is comparable is itself a signal about which agent has a better understanding of your property type and local buyer behaviour.

If two of the three agents used similar comparables and reached similar conclusions, and the third used a different selection and reached a significantly different number, the outlier warrants scrutiny. It may be correct - the third agent may have identified a comparable the others missed. Or it may reflect the listing acquisition motivation.

Pricing at the defensible value produces a stronger outcome than pricing above it. Overpriced properties attract fewer buyers, spend more days on market, and are often sold for less than they would have achieved at a realistic entry price - because the extended campaign communicates to buyers that something is wrong, and that perception shifts the negotiating dynamic against the vendor.

The question is not which agent told you what you wanted to hear. The question is which agent can show you the evidence behind the number they gave you.

What Vendors Most Often Ask About Property Appraisals

Can I trust a real estate agent appraisal?

A well-constructed appraisal based on relevant comparable sales and considered adjustments will typically fall within five to ten percent of the eventual sale price in a stable market. The accuracy depends on the quality of the comparable sales available, the the agent knowledge of local buyer behaviour, and the stability of market conditions at the time of the appraisal. In thin markets with low transaction volumes, or during periods of rapid price movement, the margin of error widens. An appraisal is a professional opinion, not a guaranteed price - and it should be evaluated on the quality of the evidence behind it rather than the confidence with which it is delivered.

Is it normal to get very different appraisals from different agents?

Receiving significantly different appraisals from different agents is common and does not necessarily mean any of them is wrong. Appraisals differ because comparable sales require interpretation - which sales are most relevant, how to adjust for differences between comparable properties and the subject property, and what weight to give to current market conditions. Different agents apply different judgment to the same data and reach different conclusions. The additional factor is motivation - not every appraisal is produced with the same objective, and understanding the difference between an evidence-based appraisal, a strategic recommendation, and a listing acquisition pitch is what allows a vendor to evaluate the numbers they receive.

Is the agent with the highest valuation the right one to choose?

The highest appraisal is the least reliable starting point for agent selection. It is the number most likely to reflect optimistic interpretation or a deliberate listing acquisition strategy rather than a genuine evidence-based assessment. The test is not the number itself but the evidence behind it - which comparables were used, what adjustments were made, and whether the agent can articulate the assumptions their number rests on.

What does a certified valuer do that an agent appraisal does not?

A real estate agent appraisal is a professional opinion of likely sale price, provided at no cost as part of the agent selection process. It is not a certified valuation. A formal property valuation is conducted by a licensed valuer, follows a regulated methodology, and produces a report that lenders and legal processes will accept. Certified valuations typically cost between $300 and $800 depending on property type and complexity. For most residential sales, an agent appraisal is the appropriate starting point - a formal valuation is required when a lender needs security assessment, a legal matter requires an independent opinion, or a vendor wants a certified benchmark before proceeding.

A Local Perspective on Property Appraisals

When homeowners across the Gawler District and northern Adelaide suburbs invite agents to appraise their property, the same dynamics described above apply - comparable sales that require interpretation, appraisals motivated by different objectives, and the need to identify which number is grounded in evidence rather than optimism.
Gawler East Real Estate Gawler
offers market assessments and residential property appraisals to homeowners across the Gawler District, with comparable-sales analysis that identifies the most defensible price position rather than the most flattering one - and explains the evidence behind it in terms that allow the vendor to make an informed decision.