Across the UK, businesses are under growing pressure to improve the energy efficiency of their buildings. Minimum Energy Efficiency Standards (MEES) currently prohibit the letting of commercial properties below an EPC rating of E, with government plans to raise the minimum to B by 2030. For property owners and facility managers, this shift is not just regulatory - it’s financial. Buildings with low EPC scores are becoming harder to lease, insure, or refinance.
What does an EPC rating mean?
An Energy Performance Certificate (EPC) measures a building’s efficiency on a scale from A to G, with A being the most efficient. It considers the amount of energy a property uses per square metre, its carbon emissions, and the impact of heating, lighting, and ventilation systems.
In simple terms, a higher EPC means lower running costs and a smaller carbon footprint. For example, an EPC rating D monthly cost for a typical 1,000 m² office could easily exceed that of an EPC B building by several thousand pounds per year - just in electricity and gas alone.
Why improving your EPC rating matters
Beyond compliance, improving a property’s EPC brings tangible business value:
- Lower operating costs – Efficient buildings consume less grid energy, reducing utility bills.
- Higher asset value – Energy-efficient buildings command stronger valuations and attract sustainability-focused tenants.
- Future-proofed investment – Upgrading now mitigates the risk of stranded assets as MEES tighten.
- Corporate image and ESG reporting – Demonstrating measurable carbon reductions strengthens brand reputation and compliance with sustainability frameworks.
But among all possible upgrades, few offer the combined benefits of solar power.
Recent EPC regulation changes in 2025
The UK government introduced a major overhaul of EPC assessments on 15 June 2025, designed to make ratings more accurate and better aligned with real-world energy use. The update replaced the outdated RdSAP model for existing buildings with a new methodology that considers on-site generation, battery storage, and modern heat technologies. This means solar PV systems, electric vehicle chargers, and low-carbon heating will now be weighted more positively in the scoring framework. For commercial landlords, the change brings a more realistic reflection of operational performance, encouraging direct investment in renewable technology as a route to compliance.
How solar power directly improves EPC ratings
1. On-site generation reduces carbon intensity
EPC assessments for commercial properties use the Simplified Building Energy Model (SBEM), which measures the carbon intensity of the energy a building consumes. Solar panels generate zero-carbon electricity on site, directly lowering the building’s CO₂ emissions within the model.
In many cases, installing solar PV can lift a property by one or two EPC bands, particularly when replacing grid-imported power from fossil fuels.
2. Solar lowers annual energy consumption figures
Because solar offsets a proportion of imported electricity, total annual consumption decreases. SBEM calculations reward this reduction, improving both the Building Emission Rate (BER) and Energy Use per Floor Area – two of the main variables that determine the EPC rating.
3. Solar complements efficient HVAC and lighting
Heating, ventilation, and air conditioning systems (HVAC) are major drivers of EPC scores. By powering these systems with renewable electricity, solar further reduces carbon intensity. Pairing solar PV with efficient LED lighting, variable-speed drives, or air-source heat pumps multiplies the performance gain.
4. Battery storage maximises EPC gains
For properties with variable demand, such as retail parks or manufacturing sites, adding battery storage increases the proportion of on-site solar used directly. This not only boosts the building’s efficiency but also improves resilience against grid outages and peak-time tariffs.
Complementary steps to improve EPC ratings
Solar often delivers the largest single impact, but EPC modelling also rewards efficiency upgrades such as:
- Upgrading lighting controls and occupancy sensors
- Improving insulation and building envelope performance
- Installing smart HVAC controls or heat recovery ventilation
- Switching to efficient electric heating systems powered by solar
A holistic strategy combining solar PV with energy-efficiency measures can achieve dramatic improvements – from EPC E to B or even A.
Additional benefits of solar for commercial properties
While EPC improvement is a key motivator, solar delivers broader strategic gains:
- Operational savings – Reduced grid imports lower monthly energy bills.
- Predictable budgeting – Generating your own electricity shields your business from volatile wholesale prices.
- Carbon reporting – Solar supports Scope 2 emission reductions, essential for ESG disclosures.
- Tenant appeal – Modern occupiers increasingly prioritise buildings with visible sustainability credentials.
- Tax advantages – In some cases, solar qualifies for capital allowances or enhanced depreciation schemes.
Ultimately, solar is not just a compliance tool—it’s an asset that future-proofs commercial portfolios.
The road ahead: EPC B by 2030
The government’s MEES trajectory means that properties below EPC B could soon become non-compliant. For many older offices, warehouses, and retail units, solar PV is one of the most cost-effective upgrades available.
Integrating renewable generation can transform an underperforming asset into a compliant, low-carbon, and attractive investment. When modelled correctly within SBEM, solar often provides the quickest route to EPC improvement, outperforming many fabric or mechanical upgrades in terms of return on investment.
EPC rating implications for landlords
For landlords, the EPC system isn’t just a compliance checkbox—it directly affects letting eligibility, asset value, and return on investment. Under the Minimum Energy Efficiency Standards (MEES), any property with an EPC rating below E cannot be leased unless exempt, and the long-term trajectory is toward a minimum EPC B by 2030. Non-compliance can result in penalties up to £150,000 and loss of rental income from unlettable space. With the forthcoming 2025 EPC methodology, landlords will need to act sooner rather than later to reassess portfolios and prioritise energy improvements. Installing solar power is now one of the most effective ways to achieve compliance—cutting carbon intensity while reducing running costs and improving building attractiveness to corporate tenants focused on ESG performance.
FAQs
What is an EPC rating?
An EPC rating is a government-issued measure of how energy efficient a building is, scored from A (most efficient) to G (least). It’s based on calculated energy use, carbon emissions, and system performance.
What does an EPC rating D mean for running costs?
A commercial building with an EPC D rating typically incurs significantly higher energy bills than one rated B or A. Depending on size and usage, the gap can equate to thousands of pounds per month in wasted energy.
How do solar panels improve EPC ratings?
Solar panels generate clean electricity on site, lowering a building’s reliance on grid-supplied power and cutting carbon emissions within the EPC calculation. This often results in a higher EPC grade.
What else can help improve my EPC rating?
Complementary actions include upgrading HVAC systems, switching to LED lighting, improving insulation, and adding energy-management controls. Combining these with solar maximises both energy savings and EPC performance.
What is the process of updating my EPC?
Once complete, your updated EPC is registered with the UK EPC Register and you’ll receive a digital certificate that can be shared with tenants, buyers, or lenders. It’s worth updating your EPC after major efficiency upgrades so your rating reflects your building’s true performance.
To update your EPC, you’ll need to arrange for a qualified, accredited energy assessor to visit your property. They’ll record details on heating, lighting, insulation, and any renewable systems like solar panels. The data is processed through government-approved software to produce a new rating, valid for 10 years. Costs vary depending on building size and complexity, but most commercial assessments range from a few hundred to several thousand pounds for larger premises.
In summary
For commercial property owners, how to improve EPC rating is no longer a question of comfort – it’s a matter of compliance and competitiveness. With the new EPC framework taking effect in June 2025, the assessment process now places greater emphasis on renewable generation and on-site efficiency. Solar technology stands out as a practical, scalable, and high-impact solution that aligns perfectly with these updated standards.
By generating renewable electricity on site, businesses can cut costs, improve asset value, and stay ahead of the EPC B deadline. Now is the moment to assess your building’s potential and take measurable steps toward cleaner, lower-cost energy.
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