EPC rating and sold prices in CF3 (Cardiff)
In postcode district CF3 (Cardiff), homes rated EPC C or better sold for 21% more per square metre than D–G homes (median £2,727 vs £2,262, 7,260 sales). Like for like — same size, type, build period and year — homes rated C or better sold for 2.0% less (95% range −3.0% to −0.8%). 2 of 7 sectors with enough sales show a difference distinguishable from zero. Data: HM Land Registry to 30 September 2026, EPC register.
From the raw gap to like-for-like
The homes are not alike: C+ homes here have a median floor area of 84 m² against 88 m² for D–G; the most common build period is 2012 onwards for C+ and 1950–1966 for D–G; 60% of C+ and 65% of D–G sales are detached or semi-detached houses.
| Comparing C+ with D–G homes… | Difference | 95% range |
|---|---|---|
| Raw gap per m² (medians) | +21% | — |
| Whole price, nothing held equal | +13.7% | +11.4% to +16.0% |
| Same floor area | +18.8% | +17.2% to +20.4% |
| + same property type | +16.5% | +15.1% to +17.9% |
| + same build period | +4.0% | +2.5% to +5.6% |
| + same year of sale | −2.0% | −3.0% to −0.8% |
The first row compares median prices per m²; the second compares whole prices; each later row adds one more thing that must be equal, ending with the like-for-like premium (regression of log price; build period from the certificate, 12 bands). The raw gap per m² and the whole-price gap differ because C+ and D–G homes differ in size.
Postcode sectors in CF3
| Sector | Sales | Raw gap | Like-for-like | 95% range |
|---|---|---|---|---|
| CF3 0 | 1,783 | +1% | −2.3% ▼ | −3.8% to −0.7% |
| CF3 1 | 406 | +8% | +0.9% | −2.4% to +4.3% |
| CF3 2 | 532 | +11% | −0.7% | −4.2% to +3.0% |
| CF3 3 | 1,126 | +22% | +0.6% | −2.6% to +3.8% |
| CF3 4 | 936 | +4% | −3.3% ▼ | −5.6% to −0.9% |
| CF3 5 | 985 | +15% | +0.8% | −1.8% to +3.5% |
| CF3 6 | 1,492 | +3% | −4.6% | −11.4% to +2.7% |
▲ green: premium distinguishable from zero; ▼ red: discount; plain: no measurable difference. Small areas have fewer sales, so their 95% ranges are wider.
Sold prices by EPC band in CF3
| EPC band (last certificate before sale) | Sales | Median £ per m² |
|---|---|---|
| A | 156 | £3,446 |
| B | 1,911 | £3,016 |
| C | 2,265 | £2,411 |
| D | 2,387 | £2,292 |
| E | 462 | £2,136 |
| F | 57 | £2,046 |
| G | 22 | £1,984 |
A median is shown when a band has at least 10 sales.
How this is calculated
- Every standard sale (HM Land Registry Price Paid, category A) since January 2015 is matched to the latest energy certificate of the same address (postcode + house number or name + flat) lodged from 10 years before to 3 months after the sale; sales with no certificate or an ambiguous match are left out. Across England and Wales 92% of sales match.
- Price per m² uses the certificate's total floor area (15–1,000 m²).
- Like-for-like premium: regression of the log of price on “C or better”, log floor area, property type, the certificate's build period and the year of sale. The 95% range shows how precise the estimate is; when it includes zero, the data cannot tell the premium apart from none.
Caveats
- The band is the one on the certificate before the sale; certificates are a median 0.8 years old at the sale, but a quarter are over 4 years old and some homes were improved since.
- Condition, garden, parking, views and the exact position within the sector are not known; a premium could hide in them, or they could hide one.
- Individual sales and addresses are not shown.