Why Online Property Estimates Miss: Appraisal vs Valuation in Adelaide

If you have typed your address into a property website, you have probably seen an estimated value. A second website showed a different number. An agent then gave you a third. It is common for these figures to sit tens of thousands of dollars apart.

This article explains why that happens, what a property appraisal in Adelaide actually looks at, how an appraisal differs from a bank valuation, and how to get the most out of one.

Why are online property estimates often wrong?

Online estimates are produced by automated valuation models. They take recorded sales, property attributes and suburb trends and produce a number for every address. They are a useful starting point, but they have clear blind spots.

They cannot see inside your home. A model knows land size, bedroom and bathroom counts and what nearby homes sold for. It does not know you replaced the kitchen, added a second living area, or that the bathroom has not been touched since it was built.

They average your street with the suburb. Two homes in Munno Para with the same bedroom count can sell well apart because of the block, the aspect, the street, the parking and the condition. A model smooths those differences out.

They lag the market. Estimates are built from settled sales, which can be weeks or months old by the time they are recorded. When the market moves, the estimate trails it.

They miss what is not recorded. Unapproved extensions, a granny flat, solar, or a pool that needs work are often not in the data the model uses.

How much does the lag matter right now?

It matters more in a month when the market moves quickly. Cotality reported that Adelaide dwelling values fell 1.3% in September 2026, taking the median dwelling value to $928,560. Over 12 months Adelaide is still up 6.5%.

On a home worth around $700,000, a 1.3% move is roughly $9,000. An estimate built mostly on earlier sales can be pricing the market as it was, not as it is today.

What does a property appraisal look at?

An appraisal starts with your home rather than the suburb average. When we appraise a property we walk through it and look at:

• Condition, presentation and any work that has been done.
• Layout, natural light, storage, parking and outdoor space.
• The block, the street and anything nearby that adds or takes away value.
• Recent sales that genuinely compare, and why each one is higher or lower than your home.
• What is currently for sale nearby, because those homes are your competition.
• How buyers are behaving right now, including how long homes are taking to sell and how much negotiation is happening.

The result is a price range you can sell into, with the evidence behind it, and a view on the method of sale and timing that suits your home.

What is the difference between an appraisal and a valuation?

They are often confused, but they serve different purposes.

An appraisal is an opinion from a licensed agent about what your home is likely to sell for in the current market. It guides your asking price and your campaign. It is usually free.

A valuation is a formal assessment by a certified property valuer. Lenders order valuations when you buy or refinance. They are also used in legal, family law and tax matters. A valuer may inspect the property, and the report is written for the party that ordered it.

A bank valuation often comes in below an agent's appraisal. That does not mean either is wrong. A valuation is written to protect a lender's security, so it tends to be conservative. An appraisal is an estimate of what a motivated buyer will pay in an active campaign.

When should you get an appraisal?

• Before you spend money on improvements. Some work returns more than it costs, a lot of work does not. An appraisal tells you which is which for your home.
• Six to twelve weeks before you plan to sell. That gives you time to prepare the home and plan the campaign.
• When you are refinancing. It helps to know where you stand before the lender's valuation.
• When you are reviewing an investment. A current value is part of deciding whether to hold or sell.
• After a big market move. With four rate rises in 2026 and values moving month to month, last year's figure may not hold.

What should you have ready?

• A recent council rates notice.
• A list of upgrades with rough dates and costs.
• Building approvals or certificates for extensions, carports or sheds.
• For strata or community title properties, your latest statement of fees.
• If the home is tenanted, the current lease and rent.

Having these ready makes the appraisal more accurate and saves a follow up visit.

Common questions

Is a free appraisal reliable? A good appraisal is backed by comparable sales you can check yourself. Ask the agent to show the sales they used and explain the adjustments.

Why do agents give different figures? Some agents quote high to win a listing. Ask each one for their evidence. The figure you can defend to a buyer is the one that matters.

Can I use an online estimate to set my price? Use it as a rough guide only. Pricing from an estimate that is out of date is one of the most common reasons homes sit on the market.

How do agents choose comparable sales?

The quality of an appraisal depends on the comparable sales behind it. A good set of comparables has a few things in common:

• Recent. Ideally sold in the last three to six months. In a moving market, older sales need adjusting.
• Close by. Same suburb or the next one, and ideally on similar streets.
• Similar. Similar land size, number of bedrooms and bathrooms, age, condition and style.
• Genuine sales. Arm's length sales on the open market, not transfers between family members.

When there are not enough perfect matches, a good agent widens the search carefully and explains how each sale differs from your home.

How are differences between homes adjusted?

No two homes are identical. An appraisal adjusts each comparable sale to account for the differences. Common adjustments include:

• Land size and usable yard space.
• An extra bedroom, bathroom or living area.
• Garage, carport or off street parking.
• Renovated kitchen or bathrooms.
• Heating and cooling, solar and other features.
• Position on the street, such as a busy road or a quiet court.
• General condition and presentation.

If a comparable sold for more because it had a renovated kitchen and yours has not, its price is adjusted down to make it a fair comparison, and the other way around.

What do the northern suburbs numbers show?

Suburb figures give useful context, as long as they are read carefully. Valuer General data for the March quarter 2026, published by REISA, showed Munno Para West with a median house price of $720,000 from 61 sales and annual growth above 17%. Andrews Farm had a median of $730,000 from 63 sales. Craigmore recorded growth of almost 20% from 41 sales.

These figures tell you where the suburb has been. They do not tell you what your home is worth. A suburb median mixes renovated and original homes, large and small blocks, and quiet and busy streets. Your home's value depends on how it compares with the specific sales around it.

How does the method of sale affect the price?

The appraisal gives a price range, but the method of sale can affect where in that range the final price lands.

• Private treaty sets an asking price or range and invites offers. It suits many homes in the northern suburbs and gives buyers time to arrange finance.
• Auction sets a date and lets buyers compete. It can work well when there is strong demand for a type of home, but there is no cooling off period, so buyers need to be ready.

A good appraisal includes a recommendation on method and timing, with the reasons.

What is a rental appraisal?

A rental appraisal estimates what a property would lease for. It uses the same idea as a sales appraisal, comparing the property with homes that have recently leased nearby. Investors use rental appraisals when buying, when setting rent for a new tenancy and when reviewing rent.

What does a bank valuation report include?

A lender's valuation report usually includes a description of the property, its condition, the comparable sales the valuer relied on, and a market value. The valuer may also note risks, such as a property type with limited demand. The report is prepared for the lender and you may not see the full document.

What can you do if a bank valuation comes in short?

It happens, especially when the market is moving. If a valuation comes in below the contract price:

• Ask your broker or lender whether a review is possible, and provide recent comparable sales that support the price.
• Check whether you can cover the gap with a larger deposit.
• Talk to your lender about whether another lender's valuation might differ.
• If the contract has a finance condition, speak to your conveyancer about your options before the condition date.

The best protection is to understand the evidence before you sign, so a short valuation is less likely to be a surprise.

Red flags in an appraisal

• No comparable sales are shown, or the sales are old.
• All the comparables are much larger, newer or better presented than your home.
• The appraisal is much higher than every other agent's, with no evidence.
• The agent cannot explain how they adjusted for differences.
• The appraisal ignores what is currently for sale nearby.

An appraisal you can check is worth more than a high number you cannot.

How often should you update an appraisal?

Values move. Cotality reported Adelaide dwelling values fell 1.3% in September 2026, while still being 6.5% higher over 12 months. If you had an appraisal six months ago, it may no longer reflect the market. If you are planning to sell, refinance or review an investment, a fresh appraisal is usually worthwhile.

What should you ask the agent during an appraisal?

An appraisal is also a chance to see how an agent works. Useful questions include:

• Which sales did you use, and why did you choose them?
• How did you adjust for the differences between those homes and mine?
• What is currently for sale nearby, and how does my home compare?
• How long are similar homes taking to sell right now?
• How much negotiation are buyers asking for at the moment?
• What would you fix or change before listing, and what would you leave alone?
• Which method of sale would you recommend, and why?

Clear, specific answers backed by evidence are a good sign. Vague answers and a high number with no support are not.

How does the rate environment affect value?

Interest rates affect how much buyers can borrow. The cash rate rose from 3.60% at the start of 2026 to 4.60% by September. On a $600,000 loan over 30 years, a full 1.00% increase adds about $385 a month to principal and interest repayments.

When repayments rise, lenders assess buyers at higher rates, and some buyers can borrow less. That flows through to what they can offer. An appraisal done before a series of rate rises may not reflect what buyers can pay today, which is another reason to keep it current.

Can you appraise your own home?

You can get a rough idea yourself by looking at recent sales on the major property websites, focusing on homes that are genuinely similar. Look at sold prices, not asking prices, and note the sale dates.

What is hard to judge from a screen is condition, layout and the feel of a street. That is where an agent who has been inside many of the homes nearby adds value. Use your own research as a check on the appraisal, not a replacement for it.

Get a free appraisal

Royal Realty Group appraises homes across Munno Para, Andrews Farm, Smithfield, Elizabeth, Craigmore and the wider northern suburbs. We will come to your home, walk through it with you and give you a price range with the comparable sales to back it up.

Call 0478 578 240 or email info@royalrealtygroup.com.au.

This article is general information only. Source: Cotality Home Value Index, September 2026.