EPC rating and sold prices in CF83 (Caerphilly)
In postcode district CF83 (Caerphilly), homes rated EPC C or better sold for 27% more per square metre than D–G homes (median £2,456 vs £1,939, 8,130 sales). Like for like — same size, type, build period and year — the difference is −1.0% (95% range −2.2% to +0.3%): the EPC band itself is not reflected in sale prices here. 0 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 83 m² against 86 m² for D–G; the most common build period is 2012 onwards for C+ and 1900–1929 for D–G; 70% of C+ and 54% of D–G sales are detached or semi-detached houses.
| Comparing C+ with D–G homes… | Difference | 95% range |
|---|---|---|
| Raw gap per m² (medians) | +27% | — |
| Whole price, nothing held equal | +23.6% | +21.3% to +25.8% |
| Same floor area | +25.5% | +23.7% to +27.3% |
| + same property type | +15.9% | +14.4% to +17.5% |
| + same build period | +6.9% | +5.1% to +8.6% |
| + same year of sale | −1.0% | −2.2% 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 CF83
| Sector | Sales | Raw gap | Like-for-like | 95% range |
|---|---|---|---|---|
| CF83 1 | 1,840 | +18% | −1.4% | −3.8% to +1.1% |
| CF83 2 | 1,800 | +17% | +1.0% | −1.1% to +3.1% |
| CF83 3 | 1,991 | +30% | −0.5% | −3.1% to +2.2% |
| CF83 4 | 875 | +29% | −3.0% | −7.3% to +1.4% |
| CF83 8 | 1,624 | +27% | +0.8% | −2.1% to +3.8% |
▲ 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 CF83
| EPC band (last certificate before sale) | Sales | Median £ per m² |
|---|---|---|
| A | 36 | £3,442 |
| B | 788 | £2,622 |
| C | 2,365 | £2,377 |
| D | 3,807 | £2,019 |
| E | 979 | £1,689 |
| F | 128 | £1,646 |
| G | 27 | £1,700 |
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.