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Senior Content Manager
Content specialist in office design and build.
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Sustainability is reshaping landlord responsibilities in the commercial property sector. More than three quarters of UK adults are concerned about climate change and half of employees want to see their company invest more in sustainability.
As a result, more and more firms are creating ESG strategies and setting net-zero targets. With commercial premises accounting for over half of the UK’s energy consumption, building performance is now critical for marketability.
So how do you measure that performance? An energy performance certificate (EPC) is a well-known benchmark, but it only tells part of the story. For a fuller picture, landlords and tenants are turning to frameworks like NABERS UK.
Let’s break down how they both work, their key differences and which you should prioritise.
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What is EPC?
Most people have heard of an energy performance certificate (EPC), not least because all homes have to have one. They’re also a mandatory requirement for commercial lettings and sales. Commercial EPCs are valid for ten years and must be made available to all prospective tenants and buyers.
For those who aren’t familiar, an EPC is an asset-based rating. That means it’s calculated using fixed physical characteristics – such as your windows, insulation, heating system and lighting installation.
Unfortunately, there’s no consideration of how buildings are used day-to-day – and certainly no real data. That limits how well the EPC can reflect actual building performance.
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What is NABERS UK?
NABERS UK is a relatively new rating scheme in the UK, focused on actual energy performance. It was launched in the UK in 2020 by the Better Buildings Partnership (BBP). NABERS stands for the National Australian Built Environment Rating System, so no prizes for guessing its country of origin.
Unlike the EPC system, NABERS UK is performance-based. It draws on in-use energy consumption data over a 12-month period. That includes base building energy use like HVAC and lighting, plus occupier energy use such as office equipment, plug-in appliances and lighting in tenant areas.
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Why is NABERS UK important?
As you can imagine, the NABERS UK framework provides a much more accurate estimate of real-world performance for commercial buildings. Consequently, we’re seeing the rating scheme increasingly used for office buildings – particularly new-builds targeting operational performance from the outset and major refurbishments aiming for high sustainability.
For example, Grosvenor aims to achieve a NABERS UK rating of at least 4.5 stars at all its UK office assets larger than 1,000 m² by the end of 2025. The UK Green Building Council (UKGBC) has also publicly endorsed the government’s move toward a NABERS-style operational rating to drive performance improvements in non-domestic buildings.
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NABERS UK vs EPC: Key Differences
What’s the difference between NABERS UK and EPC? Here’s how the two compare in terms of their methodology, accuracy, uptake, relevance and compatibility with ESG.
Criteria EPC (energy performance certificate) NABERS UK Methodology Asset-based – based on predicted energy use under standardised conditions Performance-based – based on actual, operational energy use over 12 months Accuracy & Credibility Limited accuracy – doesn’t reflect real-world usage and often criticised for performance gap High accuracy – independently verified and reflects true building performance Legal Status / Uptake Legally required for sales and lettings of commercial buildings in the UK Voluntary but increasingly adopted – especially for new builds and major refurbishments Tenant / Investor Relevance Limited insight into running costs or environmental performance Highly relevant – trusted by tenants and investors to assess sustainability performance ESG Reporting Compatibility Basic benchmark – limited value for in-depth ESG or net-zero reporting Strong ESG alignment – widely accepted by ESG frameworks and green finance standards
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Which rating scheme should you prioritise?
NABERS UK vs EPC comes down to performance vs compliance. While EPC is the framework that’s legally required, NABERS UK delivers stronger long-term value and differentiation. It better reflects the true tenant experience, supports investor-grade ESG reporting and aligns with net-zero ambitions.
In truth, both ratings serve different purposes and should be tackled together rather than chosen between. We regularly support landlords in improving both EPC and NABERS UK scores through sustainable design and build, often working on both simultaneously.
That extends from selecting sustainable materials and integrating smart MEP systems to planning operationally efficient layouts and implementing Cat A and Cat A+ strategies – tailored for energy performance.
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Combining EPC and NABERS UK for ESG success
As a commercial landlord, it’s vital to understand both EPC and NABERS UK. One ensures your buildings are compliant, while the other can enhance performance and marketability. All in all, combining asset-based insights with real-world data is the way to go.
If you’d like more information on improving your properties’ ESG credentials, contact Oktra’s team for a sustainability-focused refurbishment consultation. You can also learn more about sustainability ratings for new builds and fit-outs by downloading our guide to green building rating schemes.
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NABERS UK vs EPC FAQs
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What’s the difference between NABERS UK and EPC ratings?
EPC is an asset-based rating using predicted energy performance, while NABERS UK is a performance-based system using actual operational data. NABERS offers a more accurate view of real-world efficiency, whereas EPC is primarily for regulatory compliance.
Is NABERS UK mandatory for office buildings?
No, NABERS UK is voluntary. That said, it’s increasingly adopted by developers, landlords and investors with a view to meeting ESG or net-zero goals.
How can I improve my building’s EPC or NABERS rating?
To improve your EPC, upgrade insulation, HVAC systems or lighting. For NABERS, focus on operational efficiency – monitor real-time energy use, optimise building management systems and engage tenants to reduce consumption. Regular audits and commissioning help with both ratings.
Which rating do tenants care about more?
Tenants increasingly value NABERS UK because it reflects real-world energy performance, operating costs and sustainability impact – making it more relevant to ESG goals. EPC remains important legally, but it’s less useful for understanding day-to-day efficiency.
Can NABERS and EPC both apply to the same property?
Yes. EPC is a legal requirement for sale or lease, while NABERS UK can be layered on to provide a performance-based rating. Many high-performing office buildings now display both, using NABERS to go beyond EPC compliance.
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Contact us
Get in touch to discuss your potential fit out costs
020 7553 9500
info@oktra.co.uk
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