How property valuations actually work, and why an estimate is not an appraisal
A plain-language look inside a property valuation: the data, the methods, and why an instant estimate and a professional appraisal are not the same thing.
A property valuation estimates what a home would sell for today, using recent sales of similar homes, the specific facts of the property, and current market conditions. An instant online estimate does this from data alone in seconds. A professional appraisal adds a qualified valuer, usually an inspection, and formal standards. Same goal, very different depth.
Once you can see the steps behind a valuation, it is far easier to judge whether a number deserves your trust. Here is how it really works.
What is a property valuation, actually?
Most valuations estimate market value: the price a home would most likely achieve in an ordinary sale, with a willing buyer and a willing seller and no unusual pressure on either side. It is an informed estimate, not a fixed fact, and its quality depends entirely on the evidence and method behind it.
What is the difference between an estimate and an appraisal?
This is the distinction that trips people up most, so it is worth being clear.
- An estimate is an instant figure produced from data, often by software. It is fast, consistent, and perfect for orientation, but it cannot see inside a home or judge its condition.
- An appraisal is a considered valuation by a qualified professional, usually including an inspection, carried out under recognised standards. It takes longer and carries a fee, and it is what lenders rely on.
Neither is wrong. They answer the same question at different levels of rigour, and they work best together: an estimate to get your bearings, an appraisal to confirm the big decisions.
How is a valuation worked out, step by step?
A good valuation, automated or professional, rests on three things.
1. The facts of the property
Size, layout, condition, age, and the features buyers pay for or avoid. Small details matter. A ground-floor flat and a top-floor flat in the same building can be worth noticeably different amounts.
2. Comparable sales
What genuinely similar homes nearby have recently sold for, adjusted for the differences. Recent, truly comparable sales carry the most weight, because they show what buyers are actually paying now, not what sellers are asking.
3. The wider market
How prices are moving locally, how long homes take to sell, and the balance of supply and demand. A home never has a value in isolation.
What are automated valuation models, and can you trust them?
An automated valuation model, often shortened to AVM, uses software to combine sold prices, property features and trends into an instant estimate. Its strengths are speed and consistency. Its limits are real: it cannot see a new kitchen or a tired roof, and it struggles where recent sales are thin or the home is unusual.
We look at their reliability in detail in how accurate are online home value estimates. The short version: treat an instant estimate as a well-informed first draft, not the final word.
Why do two valuations disagree?
If you check several sources you may get several different numbers. That is normal. Each uses different data, different comparable homes and different assumptions. The gap between them is useful: a narrow spread means the market is easy to read for a home like yours, a wide spread means there is more uncertainty and a closer look is worth the effort.
What keeps a valuation honest?
Data tells you what homes sold for. Standards tell you how to turn that into a fair, defensible value. Professional valuers do not simply guess; they work to recognised appraisal standards, so one valuer's work is comparable to another's and neither is pulled out of thin air.
The best valuations combine accurate property facts, real comparable evidence, current market data, and consistent standards. That blend is what Apraiz is built on.
To understand what separates a trustworthy valuation from a persuasive one, read what an honest valuation looks like.
Common questions
Is an online estimate the same as a valuation?
It is one kind of valuation, an instant one produced from data. It is a good starting point, but for a decision that matters you should confirm it with a professional appraisal.
Why do valuations use sold prices rather than asking prices?
Asking prices are hopes; sold prices are facts. Recent completed sales of similar homes are the strongest evidence of what buyers will actually pay.
Do I need an appraisal to sell my home?
Not always, but an independent valuation before you list helps you set a realistic price, and a professional appraisal gives extra certainty for a high-value or unusual home.