You might be thinking about dealing with the ever increasing cost of energy by installing your own generation in the form if solar panels, or adding a home battery, better insulation or even a heat pump. Although the costs of all these are much, much cheaper than a few years ago you might still be juggling the numbers to find a way to afford it. This article could help.

The mortgage lender market has undergone a quiet transformation. What began as a niche experiment in 2019 has become a mainstream financial tool: green mortgages, which reward homeowners for buying energy‑efficient homes or installing upgrades such as solar panels, heat pumps, insulation or battery storage. These incentives now include cashback, lower interest rates, and 0% additional‑borrowing loans. But the landscape is uneven, and the benefits vary widely between lenders.

Nationwide Building Society

Nationwide offers a 0% Green Additional Borrowing facility for existing mortgage customers. Borrow between £5,000 and £20,000 over two or five years to fund solar PV, battery storage, heat pumps, insulation, glazing or EV chargers. All spending must be on approved measures and evidenced with invoices and certification. Any remaining balance after the 0% period moves to Nationwide’s Standard Mortgage Rate. Access is through the existing‑customer mortgage borrowing portal at https://www.nationwide.co.uk and requires a full affordability assessment.

Halifax

Halifax provides £1,000 cashback for existing mortgage customers who install solar PV using an MCS‑certified installer. Cashback is paid after proof of installation is uploaded. There is no preferential borrowing rate; this is a reward rather than finance. Access is via the Halifax mortgage customer dashboard at https://www.halifax.co.uk.

Lloyds Bank

Lloyds offers the same £1,000 solar cashback scheme as Halifax for existing mortgage holders. Installation must be completed by an MCS‑certified installer and evidence submitted through the Lloyds mortgage portal. Details are available at https://www.lloydsbank.com.

Bank of Scotland

Bank of Scotland mirrors the Halifax and Lloyds solar cashback scheme for existing customers. Eligibility and evidence requirements are identical. Information is available at https://www.bankofscotland.co.uk

Ecology Building Society

Ecology’s C‑Change mortgage provides rate reductions linked to EPC improvement. The reduction is typically up to 0.25 percentage points per EPC band improved. This applies to renovations, retrofits and eco‑self‑builds. Access requires submitting a project plan and EPC evidence through Ecology’s application process at https://www.ecology.co.uk.

Rates can be higher than mainstream lenders even after reductions.

Barclays

Barclays offers green mortgages for A‑ and B‑rated EPC properties with a small rate reduction compared with standard products. These are primarily for new borrowing rather than existing customers. Access is through the standard mortgage application process at https://www.barclays.co.uk.

There are no retrofit incentives for existing borrowers.

NatWest

NatWest provides green mortgages for A‑ and B‑rated homes with modest rate reductions. Existing customers can apply for additional borrowing, but there are no specific retrofit incentives. Access is via the NatWest mortgage portal at https://www.natwest.com.

Virgin Money

Virgin Money offers green mortgages for A‑ and B‑rated EPC homes with small rate incentives. No retrofit incentives exist for existing customers. Access is through the standard application route at https://uk.virginmoney.com.

TSB

TSB offers green mortgages for high‑EPC homes but no retrofit incentives for existing borrowers. Access is via https://www.tsb.co.uk.

Santander

Santander provides green mortgage products for A‑ and B‑rated homes but does not offer retrofit incentives for existing customers. Access is through https://www.santander.co.uk

Leeds Building Society

Incentive: Green Additional Borrowing (discounted rate for energy‑efficiency improvements).
Access: Apply for additional borrowing; provide evidence of eligible works.
Notes: Not widely advertised; applies to insulation, glazing, heating upgrades.

Kensington Mortgages

Incentive: eKo Cashback (£1,000 for improving EPC by one band; £2,000 for two bands).
Access: Provide EPC before and after works; cashback paid after verification.
Notes: Applies to existing customers on certain products.

Saffron Building Society

Incentive: Green Further Advance (discounted rate for energy‑efficiency improvements).
Access: Apply for further advance; provide invoices and EPC evidence.
Notes: Small lender; limited availability.

Monmouthshire Building Society

Incentive: Green Additional Borrowing (discounted rate for retrofit measures).
Access: Apply for additional borrowing; provide evidence of eligible improvements.
Notes: Regional availability; modest discounts.

Newbury Building Society

Incentive: Green Further Advance (reduced rate for energy‑efficiency upgrades).
Access: Apply for further advance; provide proof of works.
Notes: Applies to insulation, glazing, heating upgrades.

Nottingham Building Society

Incentive: Green Further Advance (discounted rate for EPC‑improving works).
Access: Apply for further advance; provide EPC evidence.
Notes: Limited to certain postcodes.

How to access the benefits

Existing‑customer incentives such as Nationwide’s 0% borrowing and the Halifax‑Lloyds‑Bank of Scotland solar cashback are accessed through each lender’s online mortgage account portal.

All require evidence of installation, typically including MCS certificates, invoices and photographs. Green mortgage rate reductions for A‑ and B‑rated homes are accessed through standard mortgage applications when purchasing or remortgaging.

Negatives and constraints

Most incentives are limited to existing customers. Rate reductions for green mortgages are usually small and apply only to A‑ or B‑rated EPC homes, excluding much of the UK housing stock.

Cashback schemes rarely cover more than a small fraction of installation costs, but with installations at an all time low cost it still makes a big difference.

Many incentives apply only to:

• Solar
• Heat pumps
• Insulation
• Battery storage
• EV chargers

Upgrades like triple glazing, ventilation systems, or smart heating controls may not qualify.