EPC rating and sold prices in TW4 (Hounslow)
In postcode district TW4 (Hounslow), homes rated EPC C or better sold for 2% more per square metre than D–G homes (median £4,867 vs £4,755, 1,274 sales). Like for like — same size, type, build period and year — the difference is −0.3% (95% range −2.8% to +2.2%): 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 73 m² against 87 m² for D–G; both groups are most often built in 1930–1949; 20% of C+ and 41% of D–G sales are detached or semi-detached houses.
| Comparing C+ with D–G homes… | Difference | 95% range |
|---|---|---|
| Raw gap per m² (medians) | +2% | — |
| Whole price, nothing held equal | −12.6% | −16.1% to −8.8% |
| Same floor area | −2.9% | −5.8% to +0.1% |
| + same property type | +4.8% | +2.1% to +7.7% |
| + same build period | +5.3% | +2.5% to +8.2% |
| + same year of sale | −0.3% | −2.8% to +2.2% |
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 TW4
| Sector | Sales | Raw gap | Like-for-like | 95% range |
|---|---|---|---|---|
| TW4 5 | 628 | −5% | −2.0% | −4.9% to +1.0% |
| TW4 6 | 298 | +9% | −0.2% | −4.3% to +4.1% |
| TW4 7 | 348 | +5% | 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 TW4
| EPC band (last certificate before sale) | Sales | Median £ per m² |
|---|---|---|
| B | 135 | £4,851 |
| C | 408 | £4,922 |
| D | 580 | £4,714 |
| E | 132 | £4,794 |
| F | 14 | £5,073 |
| G | 5 | 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.