Our Methodology

The data

Every number on this site comes from official, publicly available government data. We don't make anything up and we don't guess. When we estimate, we tell you exactly how, and we label it clearly.

How we calculate savings

When you look up a property, we calculate potential savings from three improvements: insulation, solar panels, and heat pumps. Here's exactly how.

How we recalculate energy costs

EPC certificates show estimated energy costs, but these use the fuel prices from the date of assessment. A 2015 EPC uses 2015 fuel prices, which are significantly lower than today's rates. Simply showing the old figures would be misleading.

We reverse-engineer the actual energy consumption from the EPC cost data:

1. Take the EPC's cost breakdown (heating + hot water, lighting)
2. Divide by the SAP fuel prices used at the time of assessment (SAP 2009 or SAP 2012, depending on the certificate)
3. This gives us estimated kWh consumption for gas, electricity, and oil
4. Reprice at current Ofgem rates: gas 5.93p/kWh, electricity 27.69p/kWh (Q1 2026)
5. Add current standing charges

This is a conservative estimate. EPC costs only cover heating, hot water, and lighting. They do not include cooking, appliances, televisions, or electronics. Real bills are typically 30-50% higher. We tell readers this on every property page.

Landlord compliance tool

Our free landlord compliance tool checks rental properties against both current MEES (band E) and the confirmed band C requirement (October 2030). It combines data from seven government sources:

• EPC register: current rating, score, and improvement recommendations
• EPC recommendations API: specific improvements with indicative costs, mapped to published RdSAP score impacts
• ONS rental data: median rents by bedroom count and local authority, for estimating rental income impact
• Historic England: listed building detection to flag consent requirements
• Planning.data.gov.uk: conservation area checks that affect which improvements are possible
• Environment Agency: flood risk assessment from monitoring stations and warning areas
• Land Registry: last sale price for estimating property value impact

The tool calculates the cheapest path to band C, checks exemption eligibility (including the £10,000 cost cap), and lets landlords select which improvements they are planning to see whether their chosen upgrades are enough to comply.

Estimated potential ratings

Some properties have old EPCs assessed before heat pumps and solar were standard recommendations. For these, we look at neighbouring properties assessed in the last 5 years and show their average potential as a guide. This is clearly labelled with a dashed border and a note that only a qualified assessor can confirm.

How we choose our partners

We work with a small number of commercial partners, companies that install solar panels, heat pumps, and insulation, plus energy suppliers. We're selective about who we feature.

We earn a commission when you click through to a partner and make a purchase or booking. This costs you nothing extra, the commission comes from the provider. Full details in our affiliate disclosure.

Our standards

We are not a price comparison or switching service, so we do not require Ofgem Confidence Code accreditation. But we voluntarily follow its core principles because they are the right way to operate:

What we don't do

• ✗We don't collect your personal data, no forms, no phone numbers, no email harvesting
• ✗We don't estimate property values, we show Land Registry facts only
• ✗We don't sell leads to installers or energy companies
• ✗We don't use your data for profiling or targeted advertising

Questions about our methodology? Email hello@ukhomeenergyguide.co.uk