EPC rating and sold prices in SA14 (Carmarthenshire)
In postcode district SA14 (Carmarthenshire), homes rated EPC C or better sold for 28% more per square metre than D–G homes (median £1,935 vs £1,514, 5,496 sales). Like for like — same size, type, build period and year — the difference is +1.3% (95% range −0.7% to +3.3%): the EPC band itself is not reflected in sale prices here. 1 of 4 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 89 m² for D–G; the most common build period is 2012 onwards for C+ and 1900–1929 for D–G; 83% of C+ and 81% of D–G sales are detached or semi-detached houses.
| Comparing C+ with D–G homes… | Difference | 95% range |
|---|---|---|
| Raw gap per m² (medians) | +28% | — |
| Whole price, nothing held equal | +27.1% | +24.2% to +30.0% |
| Same floor area | +27.0% | +24.9% to +29.2% |
| + same property type | +22.3% | +20.4% to +24.2% |
| + same build period | +6.7% | +4.0% to +9.4% |
| + same year of sale | +1.3% | −0.7% to +3.3% |
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 SA14
| Sector | Sales | Raw gap | Like-for-like | 95% range |
|---|---|---|---|---|
| SA14 6 | 1,179 | +25% | −2.4% | −8.5% to +4.1% |
| SA14 7 | 1,346 | +21% | −0.6% | −6.5% to +5.8% |
| SA14 8 | 1,650 | +16% | +3.2% ▲ | +0.5% to +6.0% |
| SA14 9 | 1,321 | +52% | −1.9% | −6.5% to +3.0% |
▲ 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 SA14
| EPC band (last certificate before sale) | Sales | Median £ per m² |
|---|---|---|
| A | 24 | £1,719 |
| B | 975 | £2,027 |
| C | 1,120 | £1,838 |
| D | 1,810 | £1,605 |
| E | 1,151 | £1,421 |
| F | 332 | £1,364 |
| G | 84 | £1,276 |
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.