A green mortgage gives you a slightly better rate or a cash incentive because the property has a high energy rating, usually EPC band A or B. The discounts are real but small, so the honest question is what they’re worth in pounds, and the answer is a few hundred over a typical fix.
What lenders actually offer
Take a live example. Barclays Green Home Mortgages apply to new build homes bought directly from the developer with an energy efficiency score of 81 or above, which is band A or B, evidenced by the EPC or the predicted assessment on an unfinished home. Checked in September 2026, its green 5-year fix at 60% loan to value was 4.48% with an £899 fee, while the standard 5-year fix at the same loan to value on Barclays’ rates page was 4.58% with the same £899 fee. The green label was worth 0.10 percentage points there. Other lenders structure the reward as cashback on completion instead of a rate cut. Mortgage rates move often, sometimes weekly, so check the live figures before you rely on these ones.
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Green 5-year fix
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Standard 5-year fix
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Rate (60% LTV)
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4.48%
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4.58%
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Fee
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£899
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£899
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Eligibility
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New build, EPC 81+, bought direct from developer
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No EPC requirement
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The worked comparison
On a £200,000 repayment mortgage over 25 years, 4.48% costs about £1,109 a month and 4.58% about £1,121. The green deal saves roughly £11 a month, which is about £680 over the five-year fixed period, plus a slightly lower balance at the end of the fix because more of each payment clears capital. That’s the realistic scale of the benefit at today’s typical discount: a decent dinner out each quarter, not a different financial life.
The same arithmetic is how you compare a rate discount against a cashback offer. A £250 cashback beats nothing, but it loses to a 0.10 point discount on this loan size, because £680 beats £250. On a small mortgage the ranking can flip, so run the numbers on your own balance rather than assuming the rate cut always wins.
The band is what gets priced, not the number
Lenders reward the band, not the score, and Barclays’ threshold sits at 81 points. A home scoring 81 gets the same green rate as one scoring 95, and a home scoring 80 gets nothing. If you’re buying a new build, the predicted energy assessment is worth reading before you reserve, and if you’re improving an existing home towards a remortgage, the jump that matters is the one that crosses into band B. An existing certificate is easy to check, since EPCs last ten years and sit on a public register, but eligibility rules differ by lender, and the Barclays deal above is restricted to new builds bought from the developer, so an A-rated period conversion wouldn’t qualify there. Our separate article on improving your EPC rating before selling covers what actually moves the score.
Do not pay for the badge
A green mortgage should be a free bonus on a home you were buying anyway. Paying an extra £2,000 on the purchase price to secure a deal worth £680 over five years is a loss dressed as a saving. Most green ranges also sit inside one lender’s product set, so a rival’s ordinary deal can still undercut the green rate: compare the whole market on rate, fee and term first, then claim the green discount if your shortlisted lender offers one and the property qualifies.
An energy-efficient new build still completes through the ordinary legal process, and developers typically set tight exchange deadlines of 28 days or so, so once the mortgage is chosen, compare quotes from conveyancing solicitors who handle new build purchases regularly and can meet the developer’s timetable.
FAQs
Do you need a mortgage broker to get a green mortgage deal?
No, you can go direct to a lender like Barclays for their green range, same as any mortgage. A whole-of-market broker is still worth using though, since they'll check whether a green deal actually beats what's available elsewhere for your loan size and property type.
Does a green mortgage rate change if my home's EPC rating changes later?
No. The rate is fixed at completion based on the property's rating at that point, not reassessed during the deal. If your EPC rating later improves or lapses, it doesn't touch the rate you're already locked into.
Can I get a green mortgage when remortgaging, not just when buying?
Yes, most lenders offer green remortgage products alongside their green purchase deals, though eligibility criteria (like Barclays' new-build-only rule) vary a lot by lender, so it's worth checking the small print rather than assuming a green purchase deal and a green remortgage deal work the same way.
