How to read comparable sales like a valuer

Valuers work differently. They build a price opinion from evidence, and the strongest evidence is what comparable properties have actually sold for. This guide walks through how to read that evidence the way a valuer does, so you can form a grounded view of any property's likely value.

What Comparable Sales Are and Why They Matter

A comparable sale, or comp, is a property similar to the one you are assessing that has recently changed hands at a known price. The logic is simple. If a near-identical home two streets away settled at a certain figure last month, that figure tells you a great deal about what your subject property would fetch today.

Comps are the backbone of any credible price opinion because they reflect real buyer behaviour, not opinion or aspiration. A listing tells you what a seller wishes to receive. A settled sale tells you what a buyer was genuinely willing to pay and what a seller was genuinely willing to accept.

Every serious method of estimating residential value leans on comparable sales. Get the comps right and the rest of the analysis follows. Get them wrong and no amount of clever adjustment will save the number.

What Makes a Good Comp

Not every recent sale is useful. A good comp shares the core characteristics that drive value, so the differences you have to account for are small and manageable. Four tests separate a strong comp from a weak one:

• Location. The comp should sit in the same suburb or, ideally, the same pocket as the subject. Two homes can be a kilometre apart and belong to entirely different markets because of zoning, school catchments, a main road or a flood overlay.
• Property type and size. Match land area, dwelling size, build era and construction. A 1970s brick three-bedroom on 600 square metres is not a fair comp for a new four-bedroom on 320 square metres, even on the same street.
• Recency. Aim for sales that settled within the last 3 to 6 months. Markets move, and a sale from a year ago may reflect conditions that no longer apply.
• Arm's length. The sale should be a genuine transaction between unrelated parties, each acting in their own interest with no pressure or special relationship.

When a sale meets all four tests it carries real weight. When it fails one or more, you either adjust for the difference or set it aside.

How to Adjust for Differences

No two properties are identical, so valuers adjust each comp to account for how it differs from the subject. The aim is to estimate what the comp would have sold for if it shared the subject's features. The common adjustment points are:

• Land size. More land generally adds value, though the rate per square metre tapers as blocks get larger.
• Condition. A renovated kitchen and bathroom, fresh paint or a new roof lift price. Deferred maintenance pulls it down.
• Bedrooms and bathrooms. An extra bedroom or bathroom typically adds a meaningful increment, especially where it shifts the property into a different buyer bracket.
• Parking. A lock-up garage, carport or off-street space carries value, more so in dense suburbs where parking is scarce.
• Position. Aspect, outlook, noise, slope and corner blocks all move the number. A quiet leafy street beats a busy thoroughfare.
• Time and market movement. If prices have risen or fallen since the comp settled, adjust the comp toward today's conditions.

The discipline is to adjust the comp toward the subject, not the other way around. You are asking what that proven sale price would have been if the property had matched yours.

Asking Price Versus Settled Sale Price

This is where many informal estimates fall apart. An asking price is a marketing number. It is set by an agent and a seller to attract interest and it can sit above, below or close to what the market will pay.

A settled sale price is the figure recorded once the transaction completes and ownership transfers. It is the price a real buyer paid after negotiation, finance and contracts. Only settled prices tell you what the market actually did. Building an opinion on listings means building on guesses. Building it on settled sales means building on facts.

Where to Find Sales Data

Settled sales data in Australia comes from a handful of reliable channels. State and territory land registries record every transfer, and that data feeds the major property platforms.

You can access recent sales through portals such as realestate.com.au and Domain, which publish sold prices once available. Subscription tools used by professionals, including CoreLogic RP Data and Pricefinder, carry deeper sales histories and let you filter by date, land size and attributes. Council rate notices and state valuer-general data offer further reference points.

The key is to confirm a price is a settled sale rather than a listing or a withdrawn campaign. A figure with a settlement date attached is what you want.

The Traps to Avoid

• Using listings instead of sales. Advertised prices are hopes, not evidence. Anchor on settled figures.
• Cherry-picking the highest comp. It is tempting to lean on the strongest sale, but one outlier does not set the market. Use the spread, not the top.
• Ignoring a renovation difference. A comp that has been fully renovated when the subject is original will overstate value unless you adjust for the works.
• Stale comps. A sale from twelve or eighteen months ago may belong to a different market. Favour recent evidence and adjust older sales for time.
• Unusual sales. Family transfers, deceased estates, mortgagee sales and related-party deals often sit off market value. These are not arm's length and should be excluded or treated with caution.

Avoiding these traps is what separates a defensible opinion from a number that simply confirms what someone hoped to hear.

How Many Comps You Need

One comp is an anecdote. A cluster of comps is evidence. As a working guide, three to six solid, recent and well-matched sales give you enough to triangulate a reliable range.

More is not always better. Five tight, genuinely comparable sales beat fifteen loose ones, because each weak comp adds noise rather than signal. Quality of match outranks quantity every time. When your best comps cluster within a narrow band, your confidence in the conclusion rises.

A Worked Example (Illustrative Only)

The following figures are illustrative and are used only to show the method. They are not real sales and do not reflect any actual market.

Subject property: a three-bedroom, one-bathroom brick home on 580 square metres, original condition, single carport, quiet street.

Comp A settled three months ago at $720,000. It is a three-bedroom, one-bathroom home on 600 square metres but has a renovated kitchen and bathroom. Allowing roughly $30,000 for the renovation advantage and about $5,000 for the slightly larger block, adjusting the comp down toward the subject gives an indicated figure near $685,000.

Comp B settled five months ago at $660,000. It is a three-bedroom, one-bathroom home on 540 square metres in original condition, with no carport, on a similar street. The subject has a carport worth about $8,000 more and 40 square metres of extra land worth about $6,000. Adjusting up, and allowing roughly 1 per cent for market movement since settlement, gives an indicated figure near $681,000.

Both adjusted comps point to a value in the low-to-mid $680,000s. That convergence is the signal. A reasonable indicative range here would sit around $675,000 to $690,000, with the midpoint as the working figure. The example is deliberately simple. Real assessments weigh more comps and finer adjustments, but the shape of the reasoning is exactly this.

How a Desktop Opinion Applies This Systematically

A desktop price opinion takes the same logic and runs it methodically rather than by feel. It assembles a pool of recent settled sales, screens each one against the four tests, then adjusts the survivors toward the subject property. Each comp is documented, each adjustment is reasoned and the final range reflects where the adjusted comps converge. You can see exactly what that looks like in a full DeskVal sample report.

DeskVal applies this method to every property assessed, with no listing to win and no commission on the sale, so the comps chosen and the adjustments made answer to the evidence alone. If you are weighing an offer, start with the Independent Price Check ($149, under 24 hours), or choose the Full Desktop Report ($249) to see the comparable evidence and reasoning set out in full. Buyers checking a number before an offer should also read how to check a property's price before you make an offer.