Nationwide Building Society will be cutting the rate on its Green Additional Borrowing by up to 1.80% on 25 March.
This latest rate reduction means that Green Additional Borrowing will be available at 0.75% for loans of between £5,000 and £25,000 up to a maximum of 85% LTV, all of which come with no product fee.
Notable rate cuts include at the 60% LTV tier, rates will be reduced by 0.40% from 1.15% to 0.75%.
At 75% LTV, rates will be down by 0.70% from 1.45% to 0.75%, at 80% LTV, a reduction of 1.25% from 2.00% to 0.75%, and at 85% LTV, rates will be reduced by 1.80% from 2.55% to 0.75%.
The loans are only available to existing Nationwide mortgage members.
At least half of the loan must be used to fund a range of sustainable home improvements including the addition of solar panels, air source heat pumps and electric car charging points.
Nationwide will be extending its Green Additional Borrowing through mortgage brokers in the coming weeks with rates the same as those available direct.
Henry Jordan, director of mortgages at Nationwide, said: “We know more needs to be done to help people green their homes, especially as buildings are the second largest source of emissions in the UK.
“We hope by making significant cuts to the rate on Green Additional Borrowing, we are giving our members real impetus to make their existing homes greener, while ensuring we continue to play our part in tackling climate change.
“It’s great to see members like Amy and her husband benefit from our Green Additional Borrowing to make improvements to their home.
“With our green product offering our lowest ever further advance rate, we hope to see even more members look to benefit and make their homes more energy efficient in the coming year and beyond.
“We also realise that some members may look at their options via intermediaries, which is why we will start offering our Green Additional Borrowing to brokers in the coming weeks.”