VALUER

VALUER — Valuations and Lending Underwriting Energy Reduction — asked a deceptively simple question: does the energy performance of a home affect what it's worth, and what you can borrow against it? By the time the two-year project concluded in March 2022, the answer was clearly yes — and the UK had its first mortgage product specifically designed to reflect that fact.

Building directly on the LENDERS project's earlier proof of concept, VALUER brought together Monmouthshire Building Society, Rightmove, RICS, and Sero in a BEIS-funded consortium to move from theory to practice. The project implemented live green mortgage products, upgraded the tools surveyors and lenders use every day, and produced some of the most compelling data yet on the relationship between energy efficiency and property value in the UK.

The problem it addressed

Despite the existence of Energy Performance Certificates since 2007, energy performance had remained essentially invisible to the residential property market. Surveyors weren't systematically comparing it. Automated Valuation Models weren't incorporating it. And lenders certainly weren't using it to adjust what they'd lend. A home's energy rating existed on paper but had no reliable effect on its price — and no effect whatsoever on the terms of the mortgage used to buy it.

Energy performance had no financial consequence at the point of purchase — the moment it could have had most impact.

VALUER set out to change that across all three fronts simultaneously: lender affordability calculations, valuer and surveyor tools, and the data underpinning automated property valuations.

What the project delivered

A green mortgage — the first of its kind in the UK

Monmouthshire Building Society adapted its affordability calculator to incorporate LENDERS' methodology, creating the UK's first mortgage product to recognise low energy bills in its affordability assessment. For buyers purchasing a highly efficient home, maximum borrowing could increase by up to £12,000 compared to a poorly performing property of the same price — reflecting the real-world difference in monthly outgoings. The Society also launched a complementary green further advance product for existing borrowers improving their homes.

Upgraded tools for surveyors and valuers

Rightmove enhanced its Surveyor Comparator Tool (SCT) — used by professional valuers across the UK — to display EPC ratings clearly alongside other key property data when comparing comparable transactions. This gave surveyors the information they needed to systematically consider energy performance as a value factor for the first time. Rightmove also updated its Automated Valuation Model (AVM) algorithms to incorporate EPC data into estimated property values.

Updated valuation standards

RICS updated its Red Book (Valuation — Global Standards) to better reflect energy efficiency as a legitimate value differential, with substantially increased references to ESG considerations. The update took effect in January 2022 — giving the profession formal guidance to factor energy performance into their assessments.

The evidence on green value

Rightmove's analysis of 200,000 pairs of property transactions — the same homes sold twice, with different EPC ratings each time — produced the largest and most robust UK dataset yet on the relationship between energy efficiency and price.

EPC band improvement	Average price increase above market trend
1 band	+6.7%
2 bands	+12.1%
3 bands	+19.5%
4 bands	+22.0%

The AVM pilot data reinforced this: a 10-point improvement in energy efficiency score translated to an average 7.5% uplift in estimated property value. Properties with green features (double or triple glazing, solar panels, heat pumps) also sold measurably faster. And consumer behaviour was shifting: "Solar Panels" rose from the 499th most-searched keyword on Rightmove in November 2020 to 160th by November 2021. "Heat Pump" made an even more dramatic jump — from outside the top 1,000 to 209th in the same period.

The pilot areas

The project used two geofenced pilot areas in South Wales — Aspen Grove in Cardiff (a 2-mile radius, urban) and Parc Eirin in Tonyrefail (a 5-mile radius, edge-of-town new build development). Value growth at Parc Eirin during the project period outpaced both the local area baseline (+21%) and the Wales-wide average (+18%), with individual house types showing 22–31% growth.

Sero's digital decarbonisation tools — their capture survey and Pathway to Zero platform — demonstrated that both pilot properties could retrospectively reach net zero carbon by the 2030s, illustrating the scale of what the lending market could be incentivising.

Challenges and lessons

The project faced significant headwinds: Covid restrictions prevented planned face-to-face engagement on new build sites, and the pandemic-era housing market boom reduced appetite for affordability-boosting products at precisely the point when buyers could sell homes before they were finished. Engagement from estate agents and surveyors was consistently below expectations — a post-Covid in-person event in Newport attracted just one attendee from 60 invitations.

The project also found that the EPC A–rated mortgage product attracted minimal demand — since most new homes are built to EPC B — and concluded that the absence of a legal minimum EPC rating for new build homes was "entirely counterproductive." These lessons directly shaped subsequent conversations about green finance and retrofit policy.

The consortium

The project was dedicated to the memory of Professor Sarah Sayce (22 October 1950 – 22 November 2021), a pioneer in sustainable property valuation whose influence runs throughout the VALUER approach.