Sustainability Meets Lending: How EPC Data Integration Creates New Revenue Opportunities

Sophie, a senior underwriter at a mid-sized UK lender, is on her second coffee. Two near-identical cases sit in her queue: same town, similar LTVs, both vanilla salaries. On paper, either could pass with a yawn. 

Only this Tuesday isn't paper-only. 

Since spring, the lender has been pulling UPRN-matched EPC and efficiency signals into the DIP screen via TwentyCi’s EcoVal360 report. It's not there to wag a green finger. It's there to answer a blunt question: what will this home actually cost to run, and how does that affect risk, price and the customer conversation?

Case One: The "quiet winner" 

The first property, an ordinary 90s semi in Milton Keynes, shows a Current Energy Rating: C with an index score of 73 and consumption at 148 kWh/m²/yr. CO₂ sits at 3.4 tonnes/yr. Heating is a gas combi, and the report lists simple improvement steps (low-energy lighting) and pricier ones (solar PV). There's a Potential Rating of C (75) if the homeowner invests. All of this is surfaced straight from the EcoVal360 output. 

Sophie doesn't need a TED Talk. She needs a decision. The lender's pricing grid now includes a small discount for C-rated homes, plus a conditional incentive if the borrower commits to specified works that lift the rating within six months. The rule is simple because the data is explicit: current band today, potential band tomorrow, and named measures to bridge the gap. Tick. 

Two clicks later, the case is approved with a better rate and a clear condition. The customer wins a cheaper mortgage; the lender writes a book that looks a touch cleaner on energy exposure. 

Case Two: The "nearly but not quite" 

The second file looks fine on LTV and income, but the EPC picture is murkier. No recent certificate on record, and the surrounding comparables show a pattern of older heating stock and higher consumption in similar homes. That context lands on screen because EcoVal360 now returns local AVM benchmarks and ten nearest comparables, not just the subject property in a vacuum. 

Rather than a flat "no", Sophie sends it to offer with conditions: evidence of current EPC and either A) minor remedial works where the report flags simple wins, or B) a higher-priced product with no retrofit pathway. It's not box-ticking; it's routing. Triage at DIP saves the back and forth later. 

Case Three: The one you only catch at the portfolio level 

After lunch, the portfolio team kicks off its monthly sweep. The lender has a decent BTL back book and a patch of lower-rated stock they'd rather not carry into the next policy cycle. With EcoVal360 running in batch, they flag addresses that could reach Band C with two measures and target those landlords with retention + retrofit finance. That's new revenue without a new customer. Under the bonnet, the move to serverless PDF generation and batch processing keeps this realistic at scale. 

No incense was burned in the credit committee. Just better data used where it actually changes behaviour. 

What EPC data actually does for lenders 

Before we get to the three things that matter, let's acknowledge the legitimate question: how accurate are EPCs? Recent research highlights that EPC models can overstate emissions by 50% because they use standardised assumptions rather than actual occupant behaviour. That's an important finding for policymakers measuring real-world carbon reduction and for improving the models themselves. But lenders are asking a different question. What matters for lending decisions is whether the data is consistent enough to compare properties, spot relative risk, and price accordingly. A C-rated property might use less energy in practice than the model suggests, but so does every other C-rated property in the dataset. The relative ranking holds, and that's what underwrites the pricing grid. If you're measuring absolute carbon reduction for ESG disclosure, the gap between modelled and actual consumption matters. If you're working out whether the Milton Keynes semi is a better bet than the one with no certificate, you need comparative consistency, and EPCs deliver that. 

Strip away the rest and you're left with three things that move the dial: 

Price with precision. A small discount tied to the current band, plus a conditional benefit triggered by named measures to reach the potential band. No vague eco badges; precise fields. The difference between the "green mortgage" rulebook and a pricing rule that actually fires is whether your data tells you what C looks like today and what C+2 looks like in six months. That '90s semi in Milton Keynes? The system knew it was already C (73), knew it could hit C (75) with low-energy lighting, and priced accordingly. Try doing that with a manual EPC lookup and a guess. 

Cleaner triage. Route cases that need conditions at DIP, not post-valuation, and stop burning ops time. Sophie's second case—the one with no recent certificate—would've pinged back from valuation a week later if the EPC gap wasn't flagged upfront. Instead, she routed it with conditions in two minutes. That's not process improvement poetry; it's fewer phone calls and faster completions. 

Back-book income. Identify properties one or two steps from Band C and offer upgrade-linked retention or retrofit top-ups. The portfolio team's monthly sweep isn't about compliance. It's about finding BTL landlords who are close enough to Band C that a small nudge (and some finance) keeps them in your book and generates a new loan without a new customer. With some lenders already tightening criteria on sub-C properties ahead of 2028 deadlines, often without clear communication, landlords need transparency, not surprises. Show them the gap, show them the pathway, offer them the finance. That's retention, not panic. This only works if you can run batch queries across thousands of UPRNs and get back a list of "nearly there" properties with the actual measures needed. Otherwise, it's a spreadsheet exercise that dies in committee. 

The fourth benefit, better broker conversations, deserves a sentence of its own. Don't preach; show nearby properties, local benchmarks and what "good" looks like on the street. That's why the comparables page now surfaces ten lookalikes. Brokers don't want a sermon about insulation. They want to tell their client, "Three houses on your road are already C-rated, here's what they did, here's what it costs, here's what you save on the rate." 

What is EcoVal360 actually?

TwentyCi's EcoVal360 is a property-level report and API you trigger with a UPRN. You send the identifier; we return an output that combines EPC/energy data, environmental exposures, and valuation context (comparables and local benchmarks). It runs on our DOMUS platform and is built for both real-time casework and back-book sweeps. 

Think of it as an extra lens for the three calls lenders make every day: price, risk, and customer message. 

Rolling it out (and what actually breaks) 

Most lenders who try this stumble in predictable places. The tech integration is rarely the problem; APIs either work or they don't. The failure points are usually human: underwriters who ignore the new fields, BDMs who don't understand the pricing trigger, back-book sweeps that get talked about but never run. 

Here's what works, and what to watch for: 

Start with the DIP overlay. Show current band, potential band, and named measures to underwriters and pricing. Make the "conditional discount" rule live on day one. If it's optional, no one uses it. If it auto-populates and triggers a rate change, behaviour shifts fast. The risk is that underwriters route everything with a condition to avoid thinking, so you'll need to audit the first hundred cases and retrain where needed. 

Brief brokers properly, or don't bother. Give your BDMs two things: the comparables page (ten similar properties) and a one-liner on how the discount triggers. Do not give them a deck about sustainability strategy. Do not ask them to "champion the proposition". Show them the money: "C-rated property, customer commits to lighting upgrade, rate drops 10bps, here's the comparables page so they know it's real." If they can't explain it in 30 seconds on a call, they won't use it. Expect half your BDMs to ignore it for the first month, then copy the ones who are winning cases with it. 

Run the batch on BTL first. The back-book play only works if someone owns it. Portfolio teams are usually underwater, so unless you give them a named analyst and a monthly target ("find 50 landlords within two measures of Band C"), nothing happens. Start with BTL because the numbers are better. Landlords respond to retention offers that include finance for upgrades, especially if the alternative is remortgaging elsewhere at a worse rate. Residential is messier, and the incentive to act is weaker. 

Add EPC stratification to pool reports. Your treasury and investor relations teams will eventually need to talk about the energy profile of your book. If you're not tracking EPC distribution now, you'll be scrambling in twelve months when someone asks what percentage of your BTL book is below Band C. This isn't a day-one priority, but it's a month-three one. 

The pattern that kills most rollouts: treating this as a "green initiative" rather than a pricing and retention tool. If your launch comms talk about climate commitments, you've already lost half the underwriters. If you talk about conditional discounts, triage efficiency, and back-book revenue, they'll actually use it. 

What changes when the data is good 

Sophie's Tuesday didn't feel like a revolution. She priced two cases better, routed one more accurately, and didn't think about EPC again until the next file. That's the point. When energy data is embedded in the decision—not bolted on as an afterthought—it stops being a compliance checkbox and starts being a tool that makes underwriters faster, pricing sharper, and retention easier. 

The lenders who get this right won't be the ones who shout about it. They'll be the ones writing slightly better business, keeping slightly more customers, and having slightly fewer cases bounce back from valuation. 

Slightly better, done a thousand times, is how you actually move the book.