Green Mortgage and Solar Panels UK: What Lenders Offer in 2026

If you are planning to install solar panels, your mortgage could be the next thing that benefits. A solar PV array typically adds 6–10 SAP points to your home’s energy score, and that improvement often moves a Band D property into Band C — a threshold that unlocks preferential rates, cashback rewards, and interest-free borrowing from a growing number of UK lenders. Understanding how green mortgages interact with your EPC rating lets you plan the installation and the financing together, rather than treating them as separate decisions.

What is a green mortgage?

A green mortgage rewards you for owning — or improving — an energy-efficient home. Incentives come in two main forms: a lower interest rate (typically 0.1–0.2 percentage points below the lender’s standard deal) or cashback payable on completion. A smaller number of lenders offer both. Some products reward existing A/B-rated properties; others are specifically designed for homeowners borrowing extra to fund improvements including solar panels, insulation, and heat pumps.

Green mortgages are now mainstream. Over 60 UK lenders offered products in this category by 2025 — up from just four in 2019 — though they still account for only around one in nine deals on the market, according to data from the UK Sustainable Investment and Finance Association.

What EPC rating do you need?

Most green mortgage rate discounts and cashback rewards require an EPC rating of A or B. These bands correspond to SAP scores of 81 or above under the Standard Assessment Procedure that underpins every UK EPC. That is a high bar: the average UK home sits in Band D, and even a well-maintained Victorian terrace with loft insulation often reaches only Band C.

A separate category of product — sometimes called “green additional borrowing” or a “retrofit mortgage” — lends you money specifically to make improvements, without requiring a high starting EPC. Nationwide’s green additional borrowing is available to existing Nationwide mortgage holders regardless of their current rating, provided the funds go towards qualifying measures such as solar panels, insulation, or an EV charger.

The government has set a target for all rental properties in England and Wales to reach Band C by 2030. Owner-occupiers are not subject to a mandatory deadline, but the 2030 driver is already influencing how lenders design their products — and homeowners planning to remortgage in the next few years have good reason to think about their EPC now.

How solar panels improve your EPC rating

A typical 4 kWp solar array adds 6–10 SAP points to your home’s energy score. For a property in the lower half of Band D — say, a SAP score of 60 — that gain is often enough to cross the Band C threshold at SAP 69. The improvement is credited in the SAP calculation because on-site generation offsets your home’s modelled electricity import, reducing the energy cost figure the assessor records. Adding battery storage improves the credit further, because more generated electricity is used on-site rather than exported. For a full breakdown of how SAP credits solar generation, see our guide to how solar panels improve your EPC rating.

A higher EPC also supports property value independently of any mortgage benefit. Research published in Energy Economics by academics at Swansea University and the University of Birmingham found that homes with solar panels sold for 6–7% more than comparable homes without — a premium of roughly £14,000–£16,000 on a median UK home.

Lenders and what they offer

The market broadly divides into rate-discount lenders, cashback lenders, and Nationwide, which stands apart with interest-free additional borrowing. Products change frequently — always check current lender terms before applying.

Nationwide — 0% additional borrowing

Nationwide’s green additional borrowing lets existing customers borrow £5,000–£20,000 at 0% interest for two or five years, with no product fee, to fund qualifying energy improvements including solar panels. Since launching, Nationwide has lent around £60 million under the scheme — an average loan of £13,000 — and expanded it in March 2026 to reach 10,000 households. This is the closest the UK mortgage market currently comes to a government-style zero-interest green loan available through a mainstream lender.

Cashback lenders

Several high-street banks offer cashback rewards tied to EPC rating or specific upgrades. As of mid-2026:

• Barclays Greener Home Reward — cashback for A/B rated properties and for funded green upgrades, with a specific solar panel tier.
• Halifax and Lloyds Bank — Green Living and Eco Home rewards for A/B rated properties and for specific installations including solar. MoneySavingExpert maintains an up-to-date comparison of current amounts.
• HSBC Energy Efficient Homes — cashback for A/B rated properties on purchase or remortgage, with expanded availability from January 2025.
• NatWest — cashback for A/B rated homes plus additional borrowing for green improvements.
• Ecology Building Society C-Change Discounts — a rate-reduction ladder that gives a 0.25% discount for each EPC band improvement. A D-rated home that reaches B after a solar and insulation retrofit saves 0.5% off the standard variable rate. This is the most responsive product for deep-retrofit projects.

MoneySavingExpert’s green mortgages page is the most reliably updated resource for current amounts. Treat any specific cashback figure you read — including here — as a starting point for your own research, not a confirmed live offer.

Rate discounts

Across the market, green mortgage rates typically sit 0.1–0.2 percentage points below a lender’s standard comparable product, according to MoneySavingExpert. Bank of England researchers found green discounts of up to 15 basis points (0.15%) becoming embedded in mortgage pricing from around 2022. On a £250,000 mortgage, 0.15% saves around £375 a year — modest in isolation, but cumulative across multiple remortgage cycles over a 25-year term.

Green mortgages are not always the cheapest deal on the market. The discount is relative to the same lender’s non-green product; a different lender’s standard deal may still undercut it. Always compare across the whole market before committing.

Combining solar with other financing routes

Green mortgages are one tool; others complement them. If you are pre-installation and cannot yet demonstrate an improved EPC, interest-free installer finance or Nationwide’s additional borrowing can fund the panels. Once installed and a new EPC is issued, you can remortgage to a rate-discount product — capturing the installation-stage finance and the ongoing rate benefit in sequence.

For households that cannot fund the installation at all, the government’s Warm Homes Local Grant (being rolled out from 2026 via local councils) provides fully funded solar and battery storage for eligible low-income owner-occupiers. A separate 0% consumer loan scheme for solar and storage is expected from April 2027. Both routes improve your EPC in the same way and unlock the same downstream mortgage benefits. See our guide to solar panel grants for current eligibility rules.

Downsides to be aware of

The green mortgage market is fragmented and products change quickly. There is no statutory definition of a “green mortgage” in UK law and no government-backed guarantee scheme specific to energy efficiency — the permanent Mortgage Guarantee Scheme (made permanent July 2025) covers high-LTV lending generally, not green improvements. Green deals represented only 11% of available mortgage products in mid-2025, which means a better standard deal from a different lender will sometimes beat the green premium entirely.

For landlords, the 2030 EPC C minimum creates real urgency. For owner-occupiers, unlocking a marginally better remortgage rate is a thin justification for solar on its own. The stronger case for solar rests on energy bill savings, export tariff income, and payback period — the green mortgage benefit is a welcome bonus, not the primary reason to install.

How to proceed

The practical sequence: commission an EPC assessment before and after a solar installation to confirm the band movement; speak to a whole-of-market mortgage broker about which green products are available at your loan-to-value ratio; and check whether your current lender’s additional borrowing terms beat switching to a new green deal. Under the FCA’s Consumer Duty rules, brokers are now expected to raise green mortgage options proactively where relevant — ask directly if yours has not mentioned it.