EPC rating and sold prices in SA5 (Swansea)
In postcode district SA5 (Swansea), homes rated EPC C or better sold for 23% more per square metre than D–G homes (median £1,722 vs £1,401, 3,871 sales). Like for like — same size, type, build period and year — homes rated C or better sold for 2.6% more (95% range +0.4% to +4.8%). 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 87 m² for D–G; the most common build period is 1950–1966 for C+ and 1900–1929 for D–G; 58% of C+ and 48% of D–G sales are detached or semi-detached houses.
| Comparing C+ with D–G homes… | Difference | 95% range |
|---|---|---|
| Raw gap per m² (medians) | +23% | — |
| Whole price, nothing held equal | +18.8% | +15.1% to +22.6% |
| Same floor area | +21.8% | +19.0% to +24.8% |
| + same property type | +17.1% | +14.6% to +19.7% |
| + same build period | +10.5% | +7.7% to +13.4% |
| + same year of sale | +2.6% | +0.4% to +4.8% |
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 SA5
| Sector | Sales | Raw gap | Like-for-like | 95% range |
|---|---|---|---|---|
| SA5 4 | 706 | +15% | +3.0% | −2.3% to +8.6% |
| SA5 5 | 534 | +17% | +3.9% | −0.7% to +8.7% |
| SA5 7 | 593 | +12% | +4.8% | −0.2% to +10.1% |
| SA5 8 | 986 | +26% | +2.7% | −1.7% to +7.2% |
| SA5 9 | 1,052 | +21% | +2.2% | −2.1% to +6.8% |
▲ 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 SA5
| EPC band (last certificate before sale) | Sales | Median £ per m² |
|---|---|---|
| A | 3 | too few |
| B | 86 | £1,741 |
| C | 838 | £1,719 |
| D | 2,056 | £1,474 |
| E | 693 | £1,261 |
| F | 155 | £1,162 |
| G | 40 | £1,261 |
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.