EPC rating and sold prices in SG6 (North Hertfordshire)
In postcode district SG6 (North Hertfordshire), homes rated EPC C or better sold for 11% less per square metre than D–G homes (median £3,878 vs £4,336, 4,752 sales). Like for like — same size, type, build period and year — homes rated C or better sold for 1.6% less (95% range −3.1% to −0.2%). 0 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 74 m² against 88 m² for D–G; the most common build period is 2012 onwards for C+ and 1900–1929 for D–G; 27% of C+ and 54% of D–G sales are detached or semi-detached houses.
| Comparing C+ with D–G homes… | Difference | 95% range |
|---|---|---|
| Raw gap per m² (medians) | −11% | — |
| Whole price, nothing held equal | −25.8% | −27.9% to −23.7% |
| Same floor area | −11.2% | −12.7% to −9.8% |
| + same property type | −3.6% | −4.9% to −2.3% |
| + same build period | 0.0% | −1.7% to +1.7% |
| + same year of sale | −1.6% | −3.1% to −0.2% |
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 SG6
| Sector | Sales | Raw gap | Like-for-like | 95% range |
|---|---|---|---|---|
| SG6 1 | 1,228 | −12% | −0.4% | −3.2% to +2.4% |
| SG6 2 | 900 | −14% | −1.6% | −3.9% to +0.8% |
| SG6 3 | 865 | −12% | +0.7% | −5.4% to +7.3% |
| SG6 4 | 1,759 | −5% | +0.3% | −1.7% to +2.3% |
▲ 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 SG6
| EPC band (last certificate before sale) | Sales | Median £ per m² |
|---|---|---|
| A | 1 | too few |
| B | 483 | £3,750 |
| C | 1,494 | £3,904 |
| D | 2,057 | £4,326 |
| E | 611 | £4,364 |
| F | 94 | £4,507 |
| G | 12 | £4,654 |
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.