EPC rating and sold prices in AL8 (Welwyn Hatfield)
In postcode district AL8 (Welwyn Hatfield), homes rated EPC C or better sold for 4% less per square metre than D–G homes (median £5,213 vs £5,423, 1,948 sales). Like for like — same size, type, build period and year — the difference is +1.1% (95% range −0.6% to +3.0%): the EPC band itself is not reflected in sale prices here. 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 79 m² against 92 m² for D–G; both groups are most often built in 1950–1966; 30% of C+ and 53% 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 | −16.9% | −20.5% to −13.2% |
| Same floor area | −6.3% | −8.5% to −4.1% |
| + same property type | +0.9% | −1.0% to +2.9% |
| + same build period | +3.0% | +1.0% to +4.9% |
| + same year of sale | +1.1% | −0.6% to +3.0% |
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 AL8
| Sector | Sales | Raw gap | Like-for-like | 95% range |
|---|---|---|---|---|
| AL8 6 | 955 | −2% | +4.9% ▲ | +2.3% to +7.5% |
| AL8 7 | 993 | −8% | −1.1% | −3.5% to +1.3% |
▲ 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 AL8
| EPC band (last certificate before sale) | Sales | Median £ per m² |
|---|---|---|
| B | 77 | £5,397 |
| C | 639 | £5,200 |
| D | 988 | £5,428 |
| E | 201 | £5,446 |
| F | 39 | £4,743 |
| G | 4 | too few |
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.