Methodology and sources

Does a better energy rating (EPC) sell for more on your street? For every postcode sector in England and Wales with enough sales: sold prices per square metre by EPC band, the raw gap between C-or-better and D-to-G homes, and the like-for-like difference once size, type, build period and year of sale are taken into account — plus how much gas homes really use compared with what their certificates suggest.

The short answer

Homes with a better energy rating do sell for more per square metre, but mostly because they are different homes: newer, of different sizes and types. Once floor area, property type, build period and year of sale are held equal, the premium for an EPC of C or better is close to zero across England and Wales, and in most postcode sectors it cannot be told apart from zero.

Data and matching

• HM Land Registry Price Paid Data: standard sales (category A) of houses and flats since January 2015.
• Energy Performance of Buildings Register: domestic certificates for England and Wales (bulk download). Each sale is matched to the latest certificate of the same address lodged from 10 years before to 3 months after the sale; 92% of sales match, 0.2% are ambiguous and dropped. Independent checks of 12 random matches against the Land Registry and EPC APIs found 12 correct.
• Pages exist for postcode sectors with at least 30 matched sales and at least 10 in each group (C or better; D to G), and for postcode districts with 100 and 30.

Gas comparison

DESNZ publishes weather-corrected gas use per meter by postcode (postcodes with fewer than 5 meters are suppressed). We compare its median with the energy implied by the certificates of gas-heated homes in the same postcode (primary energy per m² × floor area ÷ 1.13). Certificates estimate use under standard occupancy; real households in poorly rated homes heat less, so certificates overstate their use (the “prebound effect”).

Conservation areas: homes and permitted development

• Boundaries: conservation areas from planning.data.gov.uk (current areas only; areas published only as a point have no boundary and no homes counted). Each home with an energy certificate is placed by the OS Open UPRN coordinates of its address; a check of 20 points against the planning.data.gov.uk API agreed 20 times. Placing homes by postcode centre instead would misplace about 5%.
• Homes: the latest certificate of each UPRN in the bulk EPC register, classified from its wall, roof, heating and window descriptions (solid or cavity wall, insulation; loft insulation depth; gas boiler, heat pump, electric, oil and others). An area page exists when at least 30 homes have a certificate and the wall, roof and heating descriptions are filled for at least 80% of them.
• Rules: England's permitted development rules for houses — General Permitted Development Order 2015, Schedule 2, Part 1 (alterations, cladding, windows) and Part 14 (solar, air source heat pumps), text as in force on 21 October 2026. They do not apply to flats in the same way, to listed buildings (listed building consent is needed), or where an Article 4 direction removes the right.
• Article 4: directions published on planning.data.gov.uk that overlap an area by more than 1% of its area; when the published data names the removed rights (for example 1A, 14A, 14G), the page applies them. Not every council publishes its directions, and the pages say so.
• Guides by measure (heat pumps, solar panels, external wall insulation, windows): region and England figures count each home inside a conservation area once, even if it lies inside two overlapping areas; shares are of the homes whose latest certificate records that feature (solar panels: of all homes). Area figures are those of the area pages.
• Postcode checker: a postcode is inside a conservation area when its centre in the ONS Postcode Directory (August 2026, live postcodes) lies inside the boundary, or when every home whose latest certificate carries that postcode has its OS Open UPRN point inside; partly inside when only some of those homes are. Councils with fewer than 0.75% of their postcodes inside any area in planning.data.gov.uk are listed as having missing or incomplete boundaries.

Can the local grid take heat pumps?

• Street level, where the network operator publishes it: spare demand capacity of local (11 kV or 6.6 kV to 400 V) substations — UK Power Networks (utilisation band × transformer rating, low end of the band; 15 June 2026), SP Electricity North West (transformer demand headroom; 24 March 2026) and Northern Powergrid (transformer headroom from last year's maximum demand; 3 August 2026). kVA and kW are treated as equal.
• Homes a substation feeds: UK Power Networks — postcodes (ONS Postcode Directory, August 2026, live residential) whose centre lies inside the published supply area; Northern Powergrid — the postcodes it lists for the substation; SP Electricity North West — the nearest substation within 1 km (no supply areas are published). A postcode linked to several substations is shared equally.
• Heat pumps a substation can take = spare capacity ÷ 1.7 kW, the after-diversity winter peak of a heat pump measured across about 700 heat pumps in the government's Renewable Heat Premium Payment trial (Love et al., Applied Energy 204, 2017); 3 kW is shown as a cold-snap case. That number is shared among the gas-heated homes (latest certificate: mains gas) on all the substation's postcodes; a sector adds up its postcodes.
• SSEN Distribution publishes no street-level capacity, so in its southern England area the sector pages use the primary substation (33/11 kV): winter demand headroom for 2027, lowest of the scenarios in its Network Scenario Headroom Report 2026, and postcodes inside its published supply area — clearly marked as a district, not a street, figure.
• The answer is shown when at least 70% of a sector's gas-heated homes with a certificate are on linked postcodes and there are at least 30. National Grid Electricity Distribution and SP Energy Networks do not publish street substation capacity openly, so sectors they serve have no answer.
• Checks of the matching (November 2026): the substation's own point lies inside its supply area for 99.9% of UK Power Networks substations, within 500 m of a postcode it feeds for 99.2% of Northern Powergrid ones, inside its primary substation's area for 99.0% of SP Electricity North West ones and for 424 of 425 SSEN primary substations; SP Electricity North West's headroom agrees in sign with its own 2026 forecast for 95% of substations; Northern Powergrid's two datasets agree on transformer rating for 99% of substations; for 24 random substations, homes with a certificate on their postcodes were a median 79% of the customers the operator reports; 36 random records re-read from the operators' live data matched the files used.

Sources and licences