How to Improve Your Commercial EPC Rating
If your commercial building has scored poorly — or you’re facing the minimum rating needed to let it — the good news is that an EPC rating is rarely fixed. A handful of well-chosen measures can often move a building from F or G up to E or beyond. The trick is knowing which changes actually shift the score, because a commercial EPC rates the building and its fixed systems, not your habits. This guide explains the measures that genuinely move the needle, roughly in order of bang-for-buck, and how to plan them.
First, a quick reminder of how the rating is worked out: a commercial EPC is calculated using government-approved software called SBEM (the Simplified Building Energy Model), which models the building’s fabric, heating, cooling, lighting and ventilation. To improve the rating, you have to improve the things SBEM measures — which is why “turn the lights off at night” doesn’t help, but “replace the lighting” does.
Start here: get a recommendations report and target the right measures
Every commercial EPC comes with a recommendations report listing suggested improvements and an indication of each one’s impact. That’s your starting map. But the headline list doesn’t always reflect your building’s biggest weakness — a proper assessment, or a quick conversation with your assessor, will tell you which measures give the most uplift per pound for your specific property. Doing the wrong improvements first is the most common way to waste money here. (We can model this for you — see the call-to-action below.)
1. Upgrade the lighting (usually the best first move)
Lighting is often the single biggest, cheapest win in a commercial building, because it’s a large share of modelled energy use and relatively easy to change: – Switch to LED throughout — older fluorescent tubes and halogen fittings are heavily penalised in the calculation. – Add lighting controls — presence/occupancy sensors, daylight dimming and timers all count, because the software credits controlled lighting.
For many shops, offices and warehouses, a full LED-plus-controls upgrade alone can lift the rating a band or more.
2. Add or improve controls (cheap, high-impact)
Controls tell the software the building is run efficiently, and they’re usually inexpensive relative to their effect: – Heating controls — programmable timers, thermostats and zone controls so you’re not heating empty space. – Building management — even basic time and temperature controls on heating, cooling and ventilation help the modelled score.
Controls are frequently the best value measure after lighting because the capital cost is low.
3. Improve the heating system
Heating is a major driver of a commercial rating, so an inefficient system drags the score down: – Replace old, inefficient boilers with a high-efficiency unit, or move to a heat pump where the building suits it. – Upgrade electric heating — old direct electric heating tends to score poorly; more efficient systems or heat pumps score better. Heating upgrades cost more than lighting or controls but can deliver a large uplift on a building with ageing plant.
4. Tackle insulation and the building fabric
Reducing heat loss improves the rating, though fabric work is usually a bigger job: – Roof and loft insulation — often the most cost-effective fabric measure. – Cavity or solid wall insulation where practical. – Better glazing — draught-proofing and, where justified, upgraded glazing. Fabric improvements are worth modelling case by case; on some buildings they’re transformative, on others the payback is slower than services upgrades.
5. Sort out cooling and ventilation efficiency
For air-conditioned buildings, the cooling system is a big factor: – Service or upgrade air-conditioning to more efficient units and add proper controls. – Improve ventilation efficiency — heat recovery and controlled ventilation are credited in the model.
6. Improve metering — and consider renewables
Metering — adequate sub-metering of energy use is part of a good non-domestic assessment and supports a better-managed, better-scoring building.
On-site renewables — solar PV panels reduce the building’s modelled net energy use and can give a meaningful uplift, especially on a building with a large roof. The capital cost is higher, so model it as part of the wider plan rather than a quick fix.
Plan the measures together, then re-assess
The smartest approach is to model the combination before you spend, so you reach your target rating (E now, and ideally with headroom for the tighter standards expected later this decade) at the lowest cost. Once the work is done, you’ll need a new EPC to capture the improved rating — the old one doesn’t update automatically. For what that assessment costs, see our commercial EPC cost guide; for why the rating matters legally, see minimum EPC rating for commercial property.
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Frequently asked questions
What’s the quickest way to improve a commercial EPC rating?
Usually lighting and controls — switching to LED with occupancy sensors and adding heating controls is typically the cheapest, fastest uplift, because the software heavily rewards efficient lighting and good controls.
Why doesn’t using less energy improve my rating?
Because a commercial EPC rates the building and its fixed systems, not the occupier’s habits. Turning lights off doesn’t change the score; replacing the lighting does.
How much can I improve my rating?
It depends on the building’s starting point and weak spots, but a poor F or G building can often reach E or better with a sensible package of lighting, controls and heating measures. A proper assessment will tell you the realistic uplift.
Do I need a new EPC after making improvements?
Yes — the rating doesn’t update on its own. You need a fresh assessment to capture the better rating on the register.
Will solar panels improve a commercial EPC?
They can — on-site solar reduces the building’s modelled net energy use and can give a useful uplift, especially with a large roof. It’s a higher-cost measure, so model it within the overall plan.
Which improvements give the best value?
Generally lighting and controls first (low cost, high impact), then heating, then fabric and renewables. The best order depends on your building — modelling it first avoids spending on the wrong thing.
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