EPC rating and sold prices in SN16 (Wiltshire)
In postcode district SN16 (Wiltshire), homes rated EPC C or better sold for 4% less per square metre than D–G homes (median £3,552 vs £3,714, 2,570 sales). Like for like — same size, type, build period and year — homes rated C or better sold for 4.7% less (95% range −7.2% to −2.0%). 1 of 2 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 95 m² against 105 m² for D–G; the most common build period is 2012 onwards for C+ and before 1900 for D–G; 59% of C+ and 72% of D–G sales are detached or semi-detached houses.
| Comparing C+ with D–G homes… | Difference | 95% range |
|---|---|---|
| Raw gap per m² (medians) | −4% | — |
| Whole price, nothing held equal | −14.4% | −17.6% to −11.1% |
| Same floor area | −3.7% | −5.8% to −1.6% |
| + same property type | −0.8% | −2.8% to +1.2% |
| + same build period | −2.4% | −5.3% to +0.6% |
| + same year of sale | −4.7% | −7.2% to −2.0% |
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 SN16
| Sector | Sales | Raw gap | Like-for-like | 95% range |
|---|---|---|---|---|
| SN16 0 | 1,093 | 0% | −6.4% ▼ | −10.5% to −2.0% |
| SN16 9 | 1,477 | −8% | −2.9% | −6.1% to +0.5% |
▲ 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 SN16
| EPC band (last certificate before sale) | Sales | Median £ per m² |
|---|---|---|
| A | 34 | £4,674 |
| B | 513 | £3,658 |
| C | 648 | £3,378 |
| D | 781 | £3,667 |
| E | 421 | £3,824 |
| F | 145 | £3,731 |
| G | 28 | £3,436 |
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.