Improving the EPC Rating of a Non-Domestic Property

Key Considerations for Building Owners, Landlords, and Developers

Why Improving a Non-Domestic EPC Matters

For commercial property owners and developers, EPC performance is more than just an environmental metric it is a regulatory, financial, and asset-management issue.

Improving a non-domestic EPC rating can:

Support compliance with Minimum Energy Efficiency Standards (MEES)
Reduce operational and lifecycle energy costs
Improve let ability and asset value
Future-proof buildings against tightening regulation
Strengthen ESG and sustainability credentials

With further EPC uplifts anticipated in coming years, early and informed action is increasingly important.

Understand the Existing EPC and It’s Assumptions

The starting point for any EPC improvement strategy is a clear understanding of the current certificate. (EPC Guide)

Key checks include:

When was the existing EPC carried out, if before 2022 then we recommend a new EPC soonest¹.
Recommended measures and indicative impacts
The assumptions used within the assessment
EPC validity (certificates last 10 years)

If the building has undergone upgrades, changes of use, or refurbishment since the EPC was issued, the rating may no longer reflect reality. In many cases, commissioning a pre-assessment or EPC improvement model can identify cost-effective gains before works begin.

¹EPC modelling methodology was updated in June 2022, this was carried out to better reflect climate change requirements and the energy efficiency move away for fossil fuel based heating towards electricity based. If your EPC was carried out prior to 15^th June 2022, we recommend you have the EPC updated soonest to ensure that the building will meet current MEES requirements to ensure the building remain lettable.

Building Fabric Improvements

Enhancing the thermal performance of the building envelope can provide meaningful EPC improvements, particularly where existing insulation levels are poor, though in general thermal improvements only off incremental improvements to the EPC rating

Typical measures include:

Roof insulation – often the most cost-effective upgrade
Wall insulation – internal, external, or cavity, subject to construction
Floor insulation – particularly for ground-floor commercial units
Improved glazing and airtightness

Special care is required for listed or heritage buildings, where upgrades must balance performance with conservation and moisture management.

Heating, Cooling, and Ventilation Systems

Mechanical services have a major influence on non-domestic EPC outcomes.

Common improvement options include:

Replacing gas/oil boilers with high-efficiency condensing units or heat pumps
Upgrading HVAC plant to modern, energy-efficient systems
Introducing zoned controls, variable speed drives, and smart scheduling
Improving ventilation efficiency using heat recovery

EPCs assess asset efficiency, not how occupants use the building, so system specification and controls often matter more than behaviour.

Lighting Upgrades

Lighting improvements frequently deliver one of the best cost-to-impact ratios for EPC uplift.

Effective measures include:

Replacing fluorescent or halogen fittings with LED luminaires
Installing occupancy sensors, daylight sensors, and time controls
Optimising lighting layouts to avoid over-illumination
Installing high efficacy luminaires (> 100 lumen/watt)

Well-designed lighting controls can have a disproportionately positive effect on EPC ratings.

Building Services Controls and Energy Management

Controls play a critical role in EPC modelling and are often under-specified in older buildings.

Improvements may include:

Centralised Building Management Systems (BMS)
Time-clock optimisation for heating, cooling, and lighting
Weather compensation and load-matching controls
Sub-metering to improve energy oversight

Even where systems are not continuously monitored, EPC methodology rewards robust control strategies.

Renewable and Low-Carbon Technologies

Where feasible, renewable and low-carbon technologies can significantly improve EPC ratings.

Common options include:

Solar PV
Air-source or ground-source heat pumps

As the UK electricity grid continues to decarbonise, heat pumps increasingly outperform gas-based systems within EPC calculations.

Air Tightness and Infiltration

Reducing uncontrolled air leakage improves thermal efficiency and EPC outcomes.

Typical measures include:

Sealing gaps around windows, doors, and service penetrations
Improving draught-proofing
Undertaking air-tightness testing on larger or more complex buildings

Airtightness improvements must always be balanced with adequate ventilation to maintain indoor air quality.

Evidence, Evidence, Evidence

EPC assessors can only input what can be proven.

Providing clear evidence is essential, including:

Manufacturer specifications
Commissioning certificates
Insulation thickness and material details
Lighting layouts and control strategies

Without evidence, our assessors are required to use conservative defaults, which can materially reduce the EPC rating.

Regulatory and Compliance Context

At present, MEES requires non-domestic rented properties to achieve an EPC rating of E or above, with further tightening expected.

Additional considerations may include:

Local planning sustainability policies
Lease events and landlord obligations
Display Energy Certificate (DEC) requirements for public-sector buildings

EPC improvement strategies should always be aligned with wider compliance and asset-management objectives.

Cost, Payback, and Disruption

A successful EPC improvement strategy balances:

Capital cost versus EPC uplift
Operational energy savings
Impact on rental value and marketability
Disruption to occupiers or ongoing operations

Phasing works alongside planned refurbishments often delivers the best outcomes.

A Strategic, Evidence-Led Approach

The most effective EPC improvements follow a clear, structured process:

Review the existing EPC and building condition
Commission EPC improvement modelling
Prioritise measures with the strongest cost-to-impact ratio
Implement improvements in a coordinated sequence
Re-assess and update the EPC

This approach avoids reactive decision-making and ensures compliance is achieved efficiently and defensibly.

How Energy Report Can Help

Energy Report supports building owners, landlords, and developers with non-domestic EPC assessments, improvement modelling, and MEES compliance strategies across offices, industrial, retail, and mixed-use properties.

Our focus is on clear advice, practical solutions, and regulatory certainty—helping clients improve EPC ratings in a way that is proportionate, cost-effective, and future-proof.

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