Editorial policy

Sources

Every figure in a guide (prices, wattages, efficiency ratings, rules) must come from a source we link to. We prefer primary and official sources: the U.S. Energy Information Administration (EIA), ENERGY STAR, the U.S. Department of Energy, Ofgem, the Energy Saving Trust and manufacturers' published specifications. If we can't source a figure, we leave it out or clearly present it as an estimate and explain how we got it.

How we use AI

We use AI tools to help research and draft our guides. Every draft then goes through a fact-checking step that compares each number and claim against the listed sources, and an editorial check against this policy. Drafts that fail are rewritten or dropped. Calculations in our calculators are plain formulas you can see and check.

Independence

We don't accept payment to include or rank products. Our pages may show advertising, and some links may earn us a commission in the future; if so, the page will say it, and it never changes what we recommend.

Updates and corrections

Energy prices change every month in the US and every quarter in the UK. Each guide shows the date it was last checked, and we refresh the figures when new official data is published. If you find a mistake, email [email protected] and we'll correct it and note the change.

Not financial advice

Our guides explain costs and trade-offs in general terms. For decisions about large purchases or installations (heat pumps, solar panels), get quotes from qualified installers for your home.