Commercial buildings need a minimum EPC rating of E to be sold or let, and that minimum is set to rise under MEES reform – so an EPC that’s currently compliant may not stay that way. Improving a commercial EPC rating properly means understanding which measures actually move the needle for a given building, rather than defaulting to the most obvious (and often most expensive) fix first.
In this blog you’ll learn:
- Which measures typically deliver the biggest rating improvement
- Why sequencing matters – and where getting it wrong can cost more, not less
- How a professional energy audit changes what’s actually worth doing
Fabric and Systems EPC Rating Improvements
The measures with the most direct impact on a commercial EPC rating fall into a few categories:
- Insulation – improving wall, roof and floor insulation, and upgrading to double or triple glazing where single glazing is present
- Lighting – replacing inefficient fittings with LEDs, and adding occupancy sensors or timers to cut unnecessary use
- Heating, ventilation and air conditioning (HVAC) – upgrading ageing boilers and HVAC systems, with regular maintenance and properly optimised controls
- Appliances and equipment – replacing energy-intensive office equipment, refrigeration and other machinery with efficient alternatives
- Renewable generation – solar PV or ground source heat pumps can reduce reliance on grid electricity, though what’s viable depends heavily on the building itself
Why Sequencing These Measures Matters
Not every measure delivers value in isolation. Installing a heat pump onto a poorly insulated building, for example, can increase running costs rather than reduce them – the fabric isn’t good enough for the heat pump to run efficiently, so it ends up working harder for a worse result. Getting the fabric right first isn’t just the more thorough approach; for measures like this, it’s often the only way a later upgrade pays off at all.
At Horfield Health Centre, modelling showed that installing an air source heat pump on the building’s existing fabric would have added roughly £6,000 a year to running costs, because the insulation wasn’t good enough for the heat pump to run efficiently. Fixing the fabric first wasn’t just more thorough – it was the only way the heating upgrade would pay off at all.
Two Ways to Improve a Commercial EPC Rating Without Physical Works
Not every improvement comes from installing something. Sometimes the building’s actual performance simply isn’t being measured or credited correctly:
- An air tightness test can move a rating on its own, independent of any physical works – replacing SBEM’s pessimistic default air permeability assumption with the building’s real, measured performance. That’s what happened for two Bristol warehouses aiming for MEES compliance, where testing alone took one from a failing F to a D, and pushed the other from a high B to an A.
- Occasionally, the rating itself is the problem rather than the building. Walton Castle’s EPC jumped from a failing F (30) to a D (94) simply by correcting the assessment methodology used – moving from a residential to a commercial basis – with no physical works at all.
Monitoring and Ongoing Management
Beyond one-off measures, ongoing monitoring makes the improvement stick:
- Building automation systems – regulate lighting, temperature and ventilation automatically, based on occupancy and time schedules
- Energy monitoring and benchmarking – track usage over time and compare performance against similar buildings to catch drift before it shows up in a re-assessment
Getting a Professional Energy Audit
Working through a generic list of measures only gets you so far – the improvements that actually move a specific building’s rating depend on what’s holding that particular building back, which is exactly what an on-site energy audit is for. A qualified assessor inspects the fabric, heating and ventilation systems, and lighting in person, gathering the real data SBEM needs rather than relying on defaults or assumptions.
That’s the same evidenced approach behind the sequencing point above: an audit tells you which measure to prioritise, not just which measures exist. If your goal goes beyond the rating itself – genuinely cutting utility bills or fixing an inefficient heating system – a Commercial Energy Survey is worth considering separately. Where a Commercial EPC produces a theoretical compliance rating from a standardised model, a Commercial Energy Survey looks at how the building actually performs – real utility data, physical inspection, and a phased roadmap of operational quick wins and capital upgrades, each with a projected payback.
What’s Next?
Whether you’re working toward E for compliance, pushing further for cost and carbon reasons or trying to work out which of our services actually fits your situation, the right next step depends on what’s holding your building’s rating – or its running costs – back.
We carry out Commercial EPC assessments and energy surveys to identify the measures most likely to improve your rating.
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