EPC rating and sold prices in CF11 (Cardiff)
In postcode district CF11 (Cardiff), homes rated EPC C or better sold for 12% more per square metre than D–G homes (median £2,797 vs £2,500, 6,333 sales). Like for like — same size, type, build period and year — homes rated C or better sold for 3.9% more (95% range +2.0% to +5.8%). 1 of 5 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 67 m² against 90 m² for D–G; the most common build period is 2012 onwards for C+ and 1900–1929 for D–G; 12% of C+ and 12% of D–G sales are detached or semi-detached houses.
| Comparing C+ with D–G homes… | Difference | 95% range |
|---|---|---|
| Raw gap per m² (medians) | +12% | — |
| Whole price, nothing held equal | −9.5% | −11.6% to −7.4% |
| Same floor area | +11.4% | +9.7% to +13.2% |
| + same property type | +12.6% | +10.8% to +14.5% |
| + same build period | +8.1% | +5.9% to +10.3% |
| + same year of sale | +3.9% | +2.0% to +5.8% |
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 CF11
| Sector | Sales | Raw gap | Like-for-like | 95% range |
|---|---|---|---|---|
| CF11 0 | 1,018 | +16% | +0.4% | −3.0% to +4.0% |
| CF11 6 | 1,270 | +14% | +1.1% | −2.0% to +4.2% |
| CF11 7 | 1,333 | +23% | +3.5% ▲ | +0.2% to +6.8% |
| CF11 8 | 1,161 | +11% | +1.0% | −2.3% to +4.4% |
| CF11 9 | 1,551 | +3% | +1.9% | −0.9% to +4.8% |
▲ 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 CF11
| EPC band (last certificate before sale) | Sales | Median £ per m² |
|---|---|---|
| A | 3 | too few |
| B | 1,296 | £2,947 |
| C | 1,946 | £2,685 |
| D | 2,230 | £2,524 |
| E | 738 | £2,412 |
| F | 87 | £2,250 |
| G | 33 | £2,212 |
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.