Our method

Last reviewed 19 May 2026

Most home-energy sites won't tell you how they got their numbers. Warmworth will. This page is the public account of how we research, verify, update and correct the content on this site.

Our review cadence

UK home energy policy in 2026 moves quickly. Here's how often each part of the site is checked:

Our primary sources, in order of authority

1. The legislation itself — Acts of Parliament, Statutory Instruments, devolved-government regulations. Used for definitional questions.
2. Official guidance pages — gov.uk, gov.scot, gov.wales, nidirect.gov.uk, Ofgem, Communities NI Department, Welsh Government. Used for current eligibility, amounts and process.
3. Implementing authorities — Energy Saving Trust, Home Energy Scotland, Warmworks, Nest delivery partner, Utility Regulator NI, OZEV, MCS, TrustMark.
4. Trade press — Solar Energy UK, Energy Saving Trust briefings, Energy UK statements, Heat Pump Federation, Renewable Energy Association.
5. Specialist news — Carbon Brief, Energy & Climate Intelligence Unit, Cornwall Insight (for market data).
6. Consumer journalism — Which?, MoneySavingExpert, BBC News (used only to flag stories worth investigating directly via sources 1–4 above).

If a popular blog or installer site contradicts an official source, the official source wins. We've routinely found that affiliate sites carry stale figures — for example, several still cite the £7,500 standard BUS for all heat pumps, missing both the £2,500 air-to-air rate (live since 28 April 2026) and the £9,000 oil/LPG uplift (live from July 2026).

How we verify a scheme detail before publishing

For every individual claim about a grant amount, eligibility rule or process step, we follow a five-point check:

1. Cross-reference at least two of the official sources listed above.
2. Date-stamp the source — guidance pages without dates are flagged for fresh verification.
3. Check for amendments — many schemes have multiple amendment regulations. We trace the latest in force.
4. Check devolved differences — the same nominal scheme often has different rules in Scotland, Wales and NI.
5. Run the claim past the rules engine — if a scheme detail breaks our existing quiz logic, we treat that as a flag to dig deeper, not a reason to suppress the change.

What we do when we get something wrong

Three steps, in this order:

1. Fix the page within 48 hours of confirmation. Most corrections happen within 24 hours of someone flagging them.
2. Add a changelog entry at the bottom of the affected page, with the date of the correction, the old value, the new value, and (where applicable) the source that triggered the correction.
3. Update the rules engine if the correction affects the quiz logic. Bump the data/grants.json version number. We treat the rules engine as a versioned product, not just a content asset.

If you've spotted a mistake on the site, please send it to corrections@warmworth.co.uk with the page URL and what you believe is wrong. We aim to respond within two working days.

The rules engine: how the quiz actually works

Our eligibility quiz is not a static decision tree. It runs against a versioned JSON ruleset (data/grants.json) that's published on the site itself. Every grant in the ruleset declares:

• Its current minimum and maximum value
• The UK nations it operates in
• What it covers (insulation, solar, heat pump, etc.)
• The eligibility predicate as structured data (region, tenure, property type, heating type, income band, EPC rating, benefits, intent)
• The official application URL
• The source URL we last verified the data against
• A priority weight (used to rank matches by likely value)

When you complete the quiz, your answers are matched against every rule in the engine, and the page renders the schemes you qualify for, ranked by value. The matching happens entirely in your browser — your answers don't have to leave your device unless you opt in to email yourself the report. The rules engine is open: you can see the full ruleset at /data/grants.json.

Conflict of interest disclosures

Warmworth has the following active commercial relationships as of 19 May 2026:

• None currently signed. The site launched on 19 May 2026. Affiliate accounts are in approval queues with Heatable, Sunsave, Effective Energy Group, Octopus Referral and Pod Point. Once activated, this disclosure section will name each relationship, the typical referral value, and where on the site that referral applies.

If we ever take editorial direction from a commercial partner — for example, if a supplier pays us to write a positive review — we'll mark the page as "Sponsored" at the very top, before the headline. We've never done so. We don't intend to. If circumstances change, this paragraph will change with them.

Site-wide changelog

For per-page changelogs, see the bottom of each page. The summary below tracks structural and policy-data changes to the site as a whole.