Due to overwhelming demand, the Green Deal Home Improvement Fund is closed for applications with immediate effect.
A surge in applications over the past two days means the allocated budget has now been reached.
All applications received prior to the fund closing that satisfy the terms and conditions and meet the eligibility criteria will be honoured at the original rates.
The Green Deal Home Improvement Fund was set up to help households in England and Wales improve the energy efficiency of their homes.
Parliamentary under secretary of state for energy and climate Change Amber Rudd said: “The Green Deal Home Improvement Fund is a world first and in a short space of time it has proved extremely popular.
“We were always clear there was a budget, which is why we encouraged people to act quickly.
“As a result, thousands more families will now benefit from government help to have warmer homes which use less energy.”
Earlier this week, the Department of Energy & Climate Change announced changes to the scheme, caused by the hugely positive response since its launch at the beginning of June.
The DECC will monitor voucher redemption rates and will consider whether to launch a further offer should funds become available.