EPC rating and sold prices in SN5 (Swindon)
In postcode district SN5 (Swindon), homes rated EPC C or better sold for 1% more per square metre than D–G homes (median £3,055 vs £3,032, 6,369 sales). Like for like — same size, type, build period and year — the difference is −0.6% (95% range −1.5% to +0.3%): the EPC band itself is not reflected in sale prices here. 1 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 79 m² against 78 m² for D–G; both groups are most often built in 1983–1990; 59% 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) | +1% | — |
| Whole price, nothing held equal | +3.1% | +1.0% to +5.3% |
| Same floor area | +0.4% | −0.8% to +1.6% |
| + same property type | +2.8% | +1.7% to +3.8% |
| + same build period | +4.1% | +2.9% to +5.3% |
| + same year of sale | −0.6% | −1.5% 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 SN5
| Sector | Sales | Raw gap | Like-for-like | 95% range |
|---|---|---|---|---|
| SN5 3 | 161 | −11% | −2.2% | −8.5% to +4.6% |
| SN5 4 | 1,363 | −5% | −2.6% | −7.3% to +2.4% |
| SN5 5 | 1,764 | +4% | +0.9% | −0.6% to +2.4% |
| SN5 6 | 863 | +2% | −0.3% | −2.7% to +2.1% |
| SN5 7 | 848 | +6% | 0.0% | −1.8% to +1.8% |
| SN5 8 | 1,365 | −1% | −1.6% ▼ | −3.0% to −0.2% |
▲ 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 SN5
| EPC band (last certificate before sale) | Sales | Median £ per m² |
|---|---|---|
| A | 1 | too few |
| B | 1,049 | £2,941 |
| C | 2,505 | £3,135 |
| D | 2,439 | £3,028 |
| E | 327 | £3,088 |
| F | 42 | £3,029 |
| G | 6 | too few |
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.