EPC rating and sold prices in SO23 (Winchester)
In postcode district SO23 (Winchester), homes rated EPC C or better sold for 5% less per square metre than D–G homes (median £4,800 vs £5,060, 3,623 sales). Like for like — same size, type, build period and year — homes rated C or better sold for 4.4% less (95% range −6.1% to −2.5%). 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 86 m² against 91 m² for D–G; the most common build period is 2012 onwards for C+ and before 1900 for D–G; 33% of C+ and 39% of D–G sales are detached or semi-detached houses.
| Comparing C+ with D–G homes… | Difference | 95% range |
|---|---|---|
| Raw gap per m² (medians) | −5% | — |
| Whole price, nothing held equal | −12.0% | −15.2% to −8.8% |
| Same floor area | −6.8% | −8.5% to −5.1% |
| + same property type | −4.4% | −6.0% to −2.6% |
| + same build period | −2.5% | −4.4% to −0.6% |
| + same year of sale | −4.4% | −6.1% to −2.5% |
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 SO23
| Sector | Sales | Raw gap | Like-for-like | 95% range |
|---|---|---|---|---|
| SO23 0 | 752 | +1% | +4.9% ▲ | +1.4% to +8.5% |
| SO23 7 | 1,673 | −5% | −4.5% ▼ | −6.9% to −2.0% |
| SO23 8 | 539 | −4% | −2.3% | −6.8% to +2.4% |
| SO23 9 | 659 | −10% | −1.7% | −5.9% to +2.6% |
▲ 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 SO23
| EPC band (last certificate before sale) | Sales | Median £ per m² |
|---|---|---|
| A | 22 | £5,001 |
| B | 368 | £5,000 |
| C | 1,297 | £4,714 |
| D | 1,485 | £5,060 |
| E | 375 | £5,128 |
| F | 63 | £5,036 |
| G | 13 | £4,286 |
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.