A further advance is when you borrow more from your current mortgage lender to fund things such as home improvements. The interest rate you pay is different to your existing mortgage and it differs to a personal loan because it is secured on your property.

The mutual will offer a discount of up to 0.69% on home loans to encourage people to ‘greenify’ their homes.

Rates start from 1% with members able to borrow between £5,000 and £25,000, up to a maximum of 90% Loan-to-Value, as part of the Green Additional Borrowing product.

At least half of the funds must be used to pay for non-structural, energy-efficient home improvements, such as solar panels, boiler upgrades, insulation and electric vehicle charging points.

The loans are only available to existing mortgage customers on no fee, two- and five-year fixed further advance rates.

There’s no product fee attached to the green additional borrowing and it’s only available direct from Nationwide in branch or by phone.

There are no restrictions on suppliers with members able to select any national or local firm when making the improvements.

Nationwide said its move to offer green home loans forms part of its £1bn pledge to reduce the carbon footprint of Britain’s homes.

Henry Jordan, Nationwide’s director of mortgages, said: “It’s becoming ever clearer there is an urgent need to reduce the carbon emissions from our homes. We believe meaningful incentives are the only realistic way to help people make their homes more sustainable, which is why we today launched our new Green Additional Borrowing product.

“This new loan is the first product we are launching as part of our wider commitment to make £1bn available to kickstart green home improvements. In this case, existing Nationwide members can borrow up to £25,000 at highly competitive rates – this is up to 0.69% lower than our standard two and five-year fixed further advance rates.

“With more than 1.5 million homes on our mortgage balance sheet, we believe offering this new loan can make a real difference as we play our part in helping to tackle the climate crisis and help members to do the same.”