EPC rating and sold prices in EN6 (Hertsmere)
In postcode district EN6 (Hertsmere), homes rated EPC C or better sold for 7% less per square metre than D–G homes (median £5,235 vs £5,631, 4,347 sales). Like for like — same size, type, build period and year — the difference is −1.3% (95% range −2.6% to 0.0%): the EPC band itself is not reflected in sale prices here. 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 84 m² against 92 m² for D–G; the most common build period is 1950–1966 for C+ and 1930–1949 for D–G; 48% of C+ and 76% of D–G sales are detached or semi-detached houses.
| Comparing C+ with D–G homes… | Difference | 95% range |
|---|---|---|
| Raw gap per m² (medians) | −7% | — |
| Whole price, nothing held equal | −9.5% | −12.6% to −6.3% |
| Same floor area | −7.7% | −9.1% to −6.3% |
| + same property type | +1.5% | +0.1% to +3.0% |
| + same build period | +0.2% | −1.2% to +1.7% |
| + same year of sale | −1.3% | −2.6% to 0.0% |
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 EN6
| Sector | Sales | Raw gap | Like-for-like | 95% range |
|---|---|---|---|---|
| EN6 1 | 1,094 | −7% | +1.1% | −1.2% to +3.5% |
| EN6 2 | 1,054 | −8% | −0.7% | −4.0% to +2.6% |
| EN6 3 | 568 | −6% | −1.1% | −3.9% to +1.8% |
| EN6 4 | 939 | −9% | −1.9% | −4.9% to +1.2% |
| EN6 5 | 692 | −5% | −2.5% | −5.1% 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 EN6
| EPC band (last certificate before sale) | Sales | Median £ per m² |
|---|---|---|
| A | 30 | £6,738 |
| B | 287 | £5,123 |
| C | 1,044 | £5,233 |
| D | 2,078 | £5,641 |
| E | 789 | £5,571 |
| F | 97 | £5,783 |
| G | 22 | £5,384 |
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.