EPC rating and sold prices in CF5 (Cardiff)
In postcode district CF5 (Cardiff), homes rated EPC C or better sold for 17% more per square metre than D–G homes (median £2,984 vs £2,548, 11,064 sales). Like for like — same size, type, build period and year — homes rated C or better sold for 1.5% less (95% range −2.8% to −0.3%). 2 of 6 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 90 m² against 91 m² for D–G; the most common build period is 2012 onwards for C+ and 1930–1949 for D–G; 53% of C+ and 47% of D–G sales are detached or semi-detached houses.
| Comparing C+ with D–G homes… | Difference | 95% range |
|---|---|---|
| Raw gap per m² (medians) | +17% | — |
| Whole price, nothing held equal | +9.7% | +7.6% to +11.8% |
| Same floor area | +14.1% | +12.7% to +15.5% |
| + same property type | +10.5% | +9.1% to +11.8% |
| + same build period | +3.9% | +2.3% to +5.5% |
| + same year of sale | −1.5% | −2.8% to −0.3% |
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 CF5
| Sector | Sales | Raw gap | Like-for-like | 95% range |
|---|---|---|---|---|
| CF5 1 | 2,228 | +16% | +4.5% ▲ | +2.2% to +6.9% |
| CF5 2 | 2,107 | +12% | −0.4% | −2.5% to +1.8% |
| CF5 3 | 2,010 | +12% | +1.1% | −1.0% to +3.2% |
| CF5 4 | 1,540 | +15% | −1.3% | −3.5% to +0.9% |
| CF5 5 | 1,248 | +10% | −1.5% | −3.6% to +0.6% |
| CF5 6 | 1,931 | +8% | −4.1% ▼ | −8.0% to 0.0% |
▲ 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 CF5
| EPC band (last certificate before sale) | Sales | Median £ per m² |
|---|---|---|
| A | 26 | £4,103 |
| B | 2,030 | £3,278 |
| C | 2,806 | £2,629 |
| D | 4,715 | £2,576 |
| E | 1,228 | £2,500 |
| F | 209 | £2,361 |
| G | 50 | £2,256 |
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.