EPC rating and sold prices in SA6 (Swansea)
In postcode district SA6 (Swansea), homes rated EPC C or better sold for 29% more per square metre than D–G homes (median £2,023 vs £1,567, 4,444 sales). Like for like — same size, type, build period and year — homes rated C or better sold for 2.6% more (95% range +0.7% to +4.5%). 2 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 81 m² against 83 m² for D–G; the most common build period is 2012 onwards for C+ and 1900–1929 for D–G; 66% of C+ and 64% of D–G sales are detached or semi-detached houses.
| Comparing C+ with D–G homes… | Difference | 95% range |
|---|---|---|
| Raw gap per m² (medians) | +29% | — |
| Whole price, nothing held equal | +27.3% | +23.3% to +31.4% |
| Same floor area | +28.6% | +25.5% to +31.7% |
| + same property type | +26.4% | +23.7% to +29.1% |
| + same build period | +8.4% | +5.9% to +10.9% |
| + same year of sale | +2.6% | +0.7% to +4.5% |
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 SA6
| Sector | Sales | Raw gap | Like-for-like | 95% range |
|---|---|---|---|---|
| SA6 5 | 1,155 | +7% | +5.1% ▲ | +1.2% to +9.2% |
| SA6 6 | 1,926 | +33% | +1.0% | −1.4% to +3.5% |
| SA6 7 | 716 | +15% | +2.6% | −2.1% to +7.5% |
| SA6 8 | 647 | +21% | +5.7% ▲ | +0.7% to +11.0% |
▲ 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 SA6
| EPC band (last certificate before sale) | Sales | Median £ per m² |
|---|---|---|
| A | 1 | too few |
| B | 273 | £2,783 |
| C | 949 | £1,890 |
| D | 2,208 | £1,648 |
| E | 807 | £1,400 |
| F | 171 | £1,344 |
| G | 35 | £1,025 |
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.