Funding words
Funding words, in plain English
Scheme documents and quotes use a lot of shorthand, and some of it is Welsh-specific. Here are the terms you're most likely to meet, each in a sentence or two.
In brief
The terms that matter most here: Nest and its two routes, the Boiler Upgrade Scheme, off-gas grid, EPC and SAP score, and the zero rate of VAT until 31 March 2027.
Checked at source on 3 November 2026 · An independent guide from SEO-DONS LTD, not the Welsh Government, Nest or a council
- Benefit route
- Nest’s route for households with a means-tested benefit in homes rated E, F or G. More
- Boiler Upgrade Scheme
- A UK government grant towards heat pumps and biomass boilers in England and Wales, applied for by an MCS installer. More
- Census 2021
- The national census taken in March 2021; table TS046 records central heating type by household.
- Crisis route
- Nest’s urgent route for eligible households with no heating or hot water. More
- Curtilage
- The land around a house that belongs to it, such as a garden or drive; used in planning rules.
- ECO4
- A supplier obligation across Great Britain to fund improvements in eligible homes; ends 31 December 2026. More
- EPC
- Energy performance certificate, rating a home A to G with a SAP score behind it. More
- G98 and G99
- The procedures for telling the network operator about a generator: notification for small systems, application for larger ones.
- Health route
- Nest’s route for households with a qualifying health condition and low income in homes rated D or lower.
- kWp
- Kilowatts peak: a solar system’s rated size.
- LPG
- Liquefied petroleum gas, from a tank or bottles; the Census calls it tank or bottled gas.
- MCS
- The certification scheme for small-scale renewable technologies and installers.
- MCS 020(a)
- The MCS standard for air source heat pump installations, including sound assessment; required for Welsh permitted development.
- Means-tested benefit
- A benefit that depends on income and savings.
- Nest
- Warm Homes Nest, the Welsh Government’s scheme for households in fuel poverty. More
- Off-gas grid
- A home not connected to mains gas, often heated by oil, LPG or electricity. More
- Permitted development
- Work allowed without a planning application, if its conditions are met. More
- PVGIS
- The EU Joint Research Centre’s solar estimator, open to anyone at no charge. More
- SAP score
- The number behind an EPC rating; Nest’s health route uses 68 or lower.
- SEG
- The scheme under which suppliers in Great Britain pay for exported electricity. More
- SP Energy Networks
- The distribution network operator for North Wales.
- Warm Homes: Local Grant
- England’s council-run low-income scheme; it doesn’t apply in Wales. More
- Warm Homes Loan Scheme
- A government loan scheme for owner-occupied homes, through participating lenders. More
- Zero rate
- A VAT rate of 0%; installed solar in homes is zero-rated until 31 March 2027, then 5%.
Where the definitions come from
The terms follow the wording of the bodies that use them: the Welsh Government's Nest report, gov.wales planning guidance, GOV.UK on the Boiler Upgrade Scheme and HMRC on VAT, read in November 2026. The full list is on our sources page.
Not sure which scheme, if any, fits your home?
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What happens next
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- We reply by email with the scheme page that fits, if there is one.
- Any application is between you and that scheme.