EPC rating and sold prices in SG5 (North Hertfordshire)
In postcode district SG5 (North Hertfordshire), homes rated EPC C or better sold for 8% less per square metre than D–G homes (median £4,222 vs £4,601, 6,879 sales). Like for like — same size, type, build period and year — homes rated C or better sold for 4.8% less (95% range −6.3% to −3.4%). 2 of 4 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 93 m² against 86 m² for D–G; the most common build period is 2012 onwards for C+ and 1900–1929 for D–G; 54% of C+ and 56% of D–G sales are detached or semi-detached houses.
| Comparing C+ with D–G homes… | Difference | 95% range |
|---|---|---|
| Raw gap per m² (medians) | −8% | — |
| Whole price, nothing held equal | −3.7% | −5.7% to −1.6% |
| Same floor area | −10.0% | −11.1% to −8.8% |
| + same property type | −6.2% | −7.3% to −5.0% |
| + same build period | −2.2% | −3.8% to −0.5% |
| + same year of sale | −4.8% | −6.3% to −3.4% |
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 SG5
| Sector | Sales | Raw gap | Like-for-like | 95% range |
|---|---|---|---|---|
| SG5 1 | 1,629 | −14% | −2.6% ▼ | −5.0% to −0.1% |
| SG5 2 | 1,324 | −3% | −0.9% | −3.4% to +1.6% |
| SG5 3 | 1,093 | +3% | +3.1% ▲ | +0.2% to +6.1% |
| SG5 4 | 2,833 | +1% | +0.1% | −2.3% to +2.5% |
▲ 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 SG5
| EPC band (last certificate before sale) | Sales | Median £ per m² |
|---|---|---|
| A | 38 | £4,807 |
| B | 1,780 | £4,219 |
| C | 2,085 | £4,206 |
| D | 2,180 | £4,607 |
| E | 662 | £4,641 |
| F | 119 | £4,167 |
| G | 15 | £4,608 |
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.