The Short Answer
In Wales it depends on your income. If you get a means-tested benefit or have a low household income, and your home is rated E or below (D with an eligible health condition), Nest can insulate it for free: call 0808 808 2244. If you earn more, Green Homes Wales lends homeowners £1,000 to £25,000 interest-free, with no means test. ECO4 is another route until 31 December 2026.
Check If Nest Would Insulate Your Home
Nest eligibility checker
Would Nest insulate your home for free?
The Welsh Government's own rules and income limits, checked 12 October 2026. About 30 seconds.
Do you own your home or rent it?
Nest
Nest is the Welsh Government's scheme for lower-income homes. Gov.wales sets three tests: you own or privately rent your home (not council or housing association); you receive a means-tested benefit or live in a low-income household; and your home is rated 54 (E) or less, or 68 (D) or less if someone has an eligible health condition. Otherwise you may go on a reserve list. Nest looks at the whole home, so insulation can come with heating or other improvements.
Green Homes Wales
The Development Bank of Wales offers interest-free loans of £1,000 to £25,000 over up to 10 years, with a six-month repayment holiday. It isn't means tested, but there are credit and affordability checks; you must own the home and live in it, listed buildings aren't currently supported, and landlords can't apply. In our view, ring Nest first for free advice, then register with the Development Bank of Wales.
ECO4
ECO4 covers Great Britain, for households on qualifying benefits or in social housing, until 31 December 2026. The Great British Insulation Scheme closed on 31 March 2026. A Nest adviser can tell you whether Nest or ECO4 suits you.
Council and Housing Association Tenants
Neither Nest nor Green Homes Wales covers council or housing association homes. Insulating them is the landlord's job, so report cold or draughty rooms in writing and ask whether the property is due for work.
If You Pay Yourself
The Energy Saving Trust puts a bare loft to 270mm at about £750 and cavity wall insulation at about £2,200 for a typical home in Great Britain. Our insulation costs guide has DESNZ's measured savings, and the loft and cavity wall guides go into each job.
Frequently Asked Questions
Don't qualify for Nest?
ECO4 ends on 31 December 2026, so if you're paying for it yourself, price is the question. Compare quotes from up to 3 local insulation installers. Free, no obligation, about 60 seconds.