EPC rating and sold prices in WD6 (Hertsmere)
In postcode district WD6 (Hertsmere), homes rated EPC C or better sold for 1% less per square metre than D–G homes (median £5,252 vs £5,294, 5,219 sales). Like for like — same size, type, build period and year — the difference is +0.6% (95% range −0.6% to +1.7%): the EPC band itself is not reflected in sale prices here. 2 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 74 m² against 85 m² for D–G; the most common build period is 2012 onwards for C+ and 1950–1966 for D–G; 21% of C+ and 45% 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 | −7.0% | −9.2% to −4.8% |
| Same floor area | −1.6% | −2.7% to −0.4% |
| + same property type | +4.8% | +3.6% to +5.9% |
| + same build period | +1.8% | +0.6% to +3.1% |
| + same year of sale | +0.6% | −0.6% to +1.7% |
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 WD6
| Sector | Sales | Raw gap | Like-for-like | 95% range |
|---|---|---|---|---|
| WD6 1 | 1,631 | −6% | −1.3% | −3.1% to +0.6% |
| WD6 2 | 1,001 | −2% | +1.0% | −1.8% to +4.0% |
| WD6 3 | 644 | +5% | +4.1% ▲ | +0.6% to +7.7% |
| WD6 4 | 814 | 0% | +1.8% | −0.6% to +4.1% |
| WD6 5 | 1,129 | +5% | +4.2% ▲ | +2.0% to +6.4% |
▲ 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 WD6
| EPC band (last certificate before sale) | Sales | Median £ per m² |
|---|---|---|
| B | 1,098 | £5,217 |
| C | 1,708 | £5,268 |
| D | 1,927 | £5,319 |
| E | 436 | £5,172 |
| F | 37 | £5,041 |
| G | 13 | £4,541 |
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.