Millions of households will be able to apply for a one-off home improvement voucher from today, as the government's new Green Homes Grant opens to the public.
The initiative, first announced in July, aims to save households cash on their energy bills by making homes more efficient whilst simultaneously helping the UK reach its net-zero carbon emission targets.
The vouchers are worth up to £5,000 and can be used on a number of energy efficiency and heating measures, such as insulation and double glazing. The government says it will cover up to two thirds of improvement costs for the average qualifying household.
However, those on the lowest incomes and in receipt of certain benefits will have 100% of their costs covered, with £10,000 to improve their homes and top-up rooms with poor circulation.
But a major flaw in the scheme could mean millions of people who desperately need the support will lose out.
New YouGov research shows as many as 9.8million property owners with poor energy efficiency want to take advantage of the scheme when it launches.
However, just 600,000 vouchers will be up for grabs from Wednesday, September 30, meaning the majority of those hoping to slash their bills will not get the support.
Of the home owners surveyed, 62% were in properties that have poor energy efficiency - which YouGov says equates to 14.9million homes in England.
From this amount, 66% said they're either "fairly interested" or "very interested" in the Green Homes Grant - the same as 9.8million households.
The government says it will assess each application individually, and not on a first come, first served basis.
Ahead of applying, households will need to visit the Simple Energy Advice (SEA) website to check if they qualify - and what support they can get.
Business and Energy Secretary, Alok Sharma, said: "Green Homes Grants are a key part of our plans to build back greener, helping make 600,000 homes more energy efficient with government vouchers, while supporting 100,000 skilled jobs and supporting our transition to net zero carbon emissions by 2050.
"From today people will have the chance to see how this scheme could help save money on their energy bills and connect to trusted local tradespeople across the country."
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How do I apply for the Green Homes Grant?

Applications for the scheme open are now open via the government's Green Homes Grant portal.
To apply, you must first use the Simple Energy Advice (SEA) website to see what energy-saving improvements can be made to your home.
The SEA website will then bring up accredited tradespeople in your area that can undertake the work - it's recommended that you get at least three quotes to make sure you're getting the best price.
Once you've found a price, apply for the voucher - but don't agree to any work until you've had your voucher confirmed.
You must make sure the work is scheduled to be completed, and the voucher redeemed subject to its terms and conditions, by March 31, 2021.
Jess Ralston, analyst at the Energy and Climate Intelligence Unit (ECIU), said: "It’s not surprising the Green Homes Grant looks to be popular amongst the public.
"This can only be good news for consumers and traders alike as bills will be reduced and jobs created all over the country, whilst also benefiting the environment.”
Peter Smith, Director of Policy and Research at the fuel poverty charity National Energy Action (NEA) said: "Millions of people across the UK face winter in properties which are dangerous or unfit for colder seasons.
"During cold spells, poor housing can lead to sharp rises in energy use, needless lives lost and avoidable stress to our highly stretched health services.
"The UK Government’s recent investment to improve the energy efficiency of our leaky housing is hugely welcome."