Five years ago, a city-centre postcode in England or Wales was, on average, more likely to be dominated by flats than it is today. That runs against the usual assumption that apartment building has been steadily squeezing houses out of UK city centres. Land Registry data for 29 city-centre postcodes shows the opposite trend in most places: 18 of the 29 saw flats fall as a share of sales between 2020 and 2025, against 11 where the share rose.
The headline numbers
Reading's RG1 postcode shows the sharpest move: flats were 59.4% of 2020 sales there, falling to 41.2% by 2025 — an 18.2 percentage-point swing in five years. Hull (HU1), Bradford (BD1), Sheffield (S1) and York (YO1) all moved by 13 points or more in the same direction. At the other end, Derby (DE1) and Oxford (OX1) moved the most the other way, gaining 7.7 and 5.7 points of flat share respectively, though neither crossed 50%.
| City (postcode) | Flat share 2020 | Flat share 2025 | Change | 2025 sales (n) |
|---|---|---|---|---|
| Derby (DE1) | 37.5% | 45.2% | +7.7pp | 166 |
| Oxford (OX1) | 24.7% | 30.4% | +5.7pp | 184 |
| Plymouth (PL1) | 61.6% | 65.4% | +3.8pp | 332 |
| Cambridge (CB1) | 18.7% | 21.8% | +3.1pp | 587 |
| Leeds (LS1) | 98.1% | 100.0% | +1.9pp | 50 |
| Wolverhampton (WV1) | 21.1% | 22.9% | +1.8pp | 83 |
| Cardiff (CF10) | 85.7% | 87.4% | +1.7pp | 222 |
| Newcastle (NE1) | 97.5% | 98.6% | +1.1pp | 70 |
| Liverpool (L1) | 97.3% | 98.1% | +0.9pp | 216 |
| Birmingham (B1) | 98.1% | 98.9% | +0.8pp | 179 |
| Bath (BA1) | 33.8% | 34.5% | +0.7pp | 696 |
| Manchester (M1) | 99.0% | 98.3% | -0.7pp | 181 |
| Middlesbrough (TS1) | 5.0% | 4.1% | -0.9pp | 122 |
| Stoke-on-Trent (ST1) | 7.8% | 6.4% | -1.4pp | 358 |
| Bristol (BS1) | 96.2% | 94.7% | -1.5pp | 207 |
| Norwich (NR1) | 46.8% | 45.2% | -1.6pp | 467 |
| Swansea (SA1) | 21.7% | 19.1% | -2.6pp | 524 |
| Exeter (EX4) | 19.1% | 16.1% | -3.0pp | 641 |
| Nottingham (NG1) | 91.7% | 88.0% | -3.7pp | 83 |
| Leicester (LE1) | 95.4% | 91.1% | -4.3pp | 56 |
| Preston (PR1) | 16.7% | 10.8% | -5.9pp | 758 |
| Portsmouth (PO1) | 41.2% | 34.9% | -6.3pp | 235 |
| Coventry (CV1) | 36.9% | 29.7% | -7.2pp | 138 |
| Southampton (SO14) | 74.6% | 64.3% | -10.3pp | 269 |
| York (YO1) | 78.7% | 65.3% | -13.3pp | 98 |
| Sheffield (S1) | 98.1% | 84.7% | -13.4pp | 72 |
| Bradford (BD1) | 92.7% | 78.4% | -14.3pp | 51 |
| Hull (HU1) | 81.3% | 64.9% | -16.4pp | 57 |
| Reading (RG1) | 59.4% | 41.2% | -18.2pp | 563 |
Based on 2025 Land Registry category-A transactions across the same 29 city-centre postcode prefixes used in an earlier ranking of flat-dominated centres; every city cleared at least 50 sales in both 2020 and 2025.
Today's most flat-dominated centres were already that way in 2020
The five centres that are over 98% flats today — Leeds, Birmingham, Newcastle, Manchester and Liverpool — were all at 97% or higher back in 2020 too (Leeds 98.1%, Birmingham 98.1%, Newcastle 97.5%, Manchester 99.0%, Liverpool 97.3%). None of them "tipped" recently. Whatever made these particular postcodes almost entirely flats — tight sorting-office boundaries drawn around a dense apartment core, little surviving pre-war terrace stock inside the line — was already true five years ago. The interesting movement in the data is happening everywhere else, in the mid-range cities where houses and flats both have a meaningful presence.
Why the fall: two different mechanisms, not one
Splitting 2020 sales by whether the Land Registry flagged them as new-build shows the decline isn't one single story.
In Reading, Bradford, Hull and Southampton, a large share of 2020's flat sales were new-build completions: 98 of Reading's 277 flat sales that year (35.4%) were new-build, 58 of Bradford's 115 (50.4%), 42 of Hull's 74 (56.8%) and 134 of Southampton's 244 (54.9%). By 2025, new-build flat sales in the same four postcodes had all but disappeared (1, 0, 11 and 4 respectively). That pattern looks like a construction wave working through: a block or two of flats completed and registered a run of first-ever sales in 2020, temporarily inflating that year's flat share, and by 2025 the building pipeline had moved on. Reading's house sales, by contrast, carried no new-build flag in either year and simply grew in volume (188 in 2020 to 330 in 2025) alongside a recovering resale flat market (179 non-new-build flat sales in 2020 rising to 231 in 2025) — the centre's overall market got busier, and the growth happened to be weighted more towards houses.
Portsmouth, York and Sheffield show a different pattern. New-build flats were a trivial share of their 2020 totals (2 of 89 in Portsmouth, 9 of 70 in York, 1 of 53 in Sheffield), so there was no completion wave to unwind. Instead, house-type sales simply grew faster than flat sales over the five years — Portsmouth's house count rose 20.5% (127 to 153) while its flat count edged down from 89 to 82; York's house sales nearly doubled (17 to 34) while flats slipped from 70 to 64.
Both mechanisms point the same direction — a falling flat share — but for different underlying reasons, and a single city-wide explanation would have missed one of them.
What this means for reading a "flat city" ranking
A single-year flat-share snapshot, including the 2025 figures used in Homecost's own ranking of the UK's most house-free city centres, can be shaped by which year you happen to catch a local building wave in. Reading's 2020 flat share (59.4%) looked like a genuinely flat-dominated centre; its 2025 figure (41.2%) looks more mixed. Neither number is wrong — they're both accurate counts of that year's actual Land Registry sales — but a reader comparing cities on a single year should treat postcodes with heavy recent new-build activity as more volatile than postcodes where the housing stock, and the sales mix, has been stable for years.
None of this is forecasting: it describes what was recorded as sold in two specific years, not what will happen next. Every property type and new-build flag used above comes directly from HM Land Registry's Price Paid data as held in Homecost's database, not from an estimate or a listing site.
Homecost's postcode tool breaks down the actual sale history behind these numbers — 2 Alpine Street in Reading's RG1, a terraced house that last sold for £350,000 in July 2025, is one of the house-type sales behind Reading's shifting mix. For the city-level price context behind these flat-share figures, see how flat share compares with city-centre prices across all 29 postcodes, or browse more market analysis on homecost.uk.