EPC rating and sold prices in DL17 (County Durham)
In postcode district DL17 (County Durham), homes rated EPC C or better sold for 89% more per square metre than D–G homes (median £1,576 vs £833, 3,126 sales). Like for like — same size, type, build period and year — the difference is −0.3% (95% range −3.6% to +3.2%): the EPC band itself is not reflected in sale prices here. 0 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 84 m² against 83 m² for D–G; the most common build period is 2012 onwards for C+ and 1900–1929 for D–G; 68% of C+ and 42% of D–G sales are detached or semi-detached houses.
| Comparing C+ with D–G homes… | Difference | 95% range |
|---|---|---|
| Raw gap per m² (medians) | +89% | — |
| Whole price, nothing held equal | +68.4% | +60.7% to +76.4% |
| Same floor area | +64.6% | +58.3% to +71.2% |
| + same property type | +29.3% | +25.1% to +33.6% |
| + same build period | +7.6% | +3.6% to +11.7% |
| + same year of sale | −0.3% | −3.6% to +3.2% |
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 DL17
| Sector | Sales | Raw gap | Like-for-like | 95% range |
|---|---|---|---|---|
| DL17 0 | 1,211 | +163% | +3.2% | −3.3% to +10.1% |
| DL17 8 | 1,319 | +32% | −1.8% | −6.0% to +2.6% |
| DL17 9 | 596 | +15% | too few | — |
▲ 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 DL17
| EPC band (last certificate before sale) | Sales | Median £ per m² |
|---|---|---|
| A | 20 | £2,357 |
| B | 470 | £1,828 |
| C | 728 | £1,101 |
| D | 1,363 | £889 |
| E | 451 | £720 |
| F | 65 | £467 |
| G | 29 | £430 |
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.