"New-build properties carry a premium that erodes the moment you resell" is one of the most repeated claims in UK property content. It's also only true for one property type. We pulled 2025 Land Registry Price Paid Data across all four main property types and split it by new-build versus resale to check the claim against actual transactions rather than repeating the received wisdom. The result is more useful than the generic version, because it tells you exactly where the effect is real and where it isn't.
The 2025 data, by property type
| Property type | Resale average price | New-build average price | New-build premium |
|---|---|---|---|
| Flats | £290,864 | £440,380 | +51.4% |
| Terraced houses | £286,264 | £292,812 | +2.3% |
| Semi-detached houses | £319,625 | £297,292 | -7.0% |
| Detached houses | £504,653 | £445,869 | -11.7% |
Source: Land Registry Price Paid Data, transactions from 1 January 2025, all England & Wales.
What this actually means
The premium the "new-build always costs more" narrative describes is real, and it's large — but it's concentrated almost entirely in flats. New-build flats sold for over 50% more than resale flats on average across 2025. That's consistent with the well-documented pattern of city-centre and near-city new-build flat developments, where developers price at a premium against limited direct comparables in a brand-new scheme, and that premium compresses hard once the same units start reappearing on the resale market a few years later — the dynamic behind pieces like why UK flats are losing value.
Houses tell a completely different story. Terraced new-build carries almost no premium at all — 2.3% is well within normal local market variation. Semi-detached and detached new-build actually sold for less on average than resale equivalents of the same type. That's not necessarily new-build houses being underpriced — it more likely reflects that new-build detached and semi-detached stock skews toward smaller, standardised estate-format homes, while the resale detached/semi-detached pool includes a wider spread of older, larger, and more individual properties that pull the resale average up. It is not, on this data, evidence that new-build houses are systematically overpriced against comparable resale stock the way new-build flats are.
The practical takeaway
If you're using "new-build premium erosion" as a BMV thesis, the data says: apply it to flats, and be sceptical of it for houses. A three-year-old resale flat priced close to its original new-build price in a scheme where recent resales are running materially lower is a legitimate signal worth investigating with a proper comparables check — see Land Registry sold-price comparison for the method. Applying the same logic to a resale semi or detached house is applying a real pattern to a property type where the underlying data doesn't support it. New-build housing supply also hit a nine-year low through 2025-2026 (covered here), which affects future new-build pricing dynamics but doesn't change what the existing stock data shows today.