How to Improve a Commercial EPC Rating (From F or G to E and Beyond)
- Start with your EPC recommendation report: it lists the measures the model expects to improve your rating, ranked by impact.
- Lighting, controls and draughtproofing are often the cheapest wins and can be enough to lift a marginal building.
- Bigger gains usually come from heating, cooling and ventilation upgrades, better glazing, insulation and on-site renewables.
- You need a fresh EPC to capture improvements: the works only change your rating once a new assessment is lodged.
Improving a commercial EPC isn't about doing everything. It's about doing the right things, in the right order, for the least money. A building sitting at F or G doesn't need a full retrofit to reach an E, and a marginal E doesn't need panic. What it needs is a clear read on which measures actually move the score for your specific building. Here's how to think about it.
Why improve the rating at all
Three reasons, and they stack. First, compliance: under MEES you generally can't let below an E, so an F or G has to move. Second, future-proofing: the minimum for larger buildings is set to rise to a B by 2031, so a strong rating protects lettability. Third, value and running costs: an efficient building is cheaper to occupy, easier to let and more attractive to buyers. Improving the rating isn't just a compliance chore, it's asset management.
Start with the recommendation report
Every EPC comes with a recommendation report listing suggested measures and their expected impact. It's the obvious starting point, and it's free once you have the certificate: look it up on Find an energy certificate. Treat it as a menu, not a mandate. The report is generated from the model, so it's a guide to what's likely to help, which you then refine with an assessor who knows your building.
The quick wins
For many buildings, a handful of low-cost measures do a lot of the work:
- LED lighting. Swapping old lighting for efficient LEDs is often the single most cost-effective improvement, especially in retail and offices.
- Lighting and heating controls. Timers, sensors, zoning and better thermostats cut waste and improve the model's score.
- Draughtproofing and small fabric fixes. Sealing gaps and sorting obvious heat loss is cheap and helps.
- Servicing and tuning plant. A well-maintained, correctly set-up heating system performs better than a neglected one.
On a marginal building, quick wins alone can be enough to cross from an F to an E.
The bigger measures
Where a building needs more, or you're aiming higher than a bare E, the larger gains usually come from:
- Heating, cooling and ventilation upgrades, including more efficient plant and, increasingly, heat pumps in place of older gas or electric heating.
- Insulation, to the roof, walls and floors where practical.
- Glazing, upgrading single glazing or poor units to modern, better-performing glass.
- Building management systems, to control and optimise services across the building.
- On-site renewables, most commonly rooftop solar, which can meaningfully shift the rating.
These cost more, so they're where cost-effective planning matters most.
Plan a better EPC rating
Get matched with accredited energy assessors who can model the most cost-effective route to a higher rating. No-obligation quotes.
Why some measures move the needle more
An EPC rating comes from a model of the building, not a meter reading. That means the impact of a measure depends on how the model treats it and how your building is built and used. A change that transforms one building's score barely shifts another's. This is exactly why the recommendation report is a starting point, not the answer: an assessor can model the specific combination of measures that gets your building to the target rating most efficiently, rather than spending on works that look sensible but move the score little.
Improvements only count once you re-assess
Here's the step people forget. Doing the works doesn't change your EPC by itself. The rating only updates when a new assessment is carried out and a fresh certificate lodged. So the sequence is: model the options, do the cost-effective measures, then commission a new EPC to capture the improved rating and put it on record. Budget for that final assessment as part of the project.
Planning it cost-effectively
The smart approach is to sequence improvements against payback and against the rating you actually need, rather than doing everything at once. For landlords with several buildings, folding EPC improvements into a wider planned maintenance programme spreads cost and avoids duplicate visits. If, after modelling, no measure passes the payback test and you still can't reach an E, that's the point at which an exemption may come into play.
Getting expert input
The difference between a cheap, effective route to a better rating and money spent on the wrong works is expert modelling. ComSurv matches you with accredited energy assessors, many of them chartered surveyors, who can advise on the most cost-effective plan and lodge the new EPC. You can check regulation via RICS Find a Surveyor.
Sources & further reading
- Non-domestic private rented property: minimum energy efficiency standard (GOV.UK) — how improvements interact with the minimum standard
- Find an energy certificate (GOV.UK) — your EPC and its recommendation report
- RICS Find a Surveyor — find RICS-regulated professionals
External links open in a new tab. ComSurv is a matching service, not a firm of surveyors, and is not affiliated with these organisations. This article is general information, not legal, surveying or valuation advice; take advice on your specific situation.
