Why most commercial buildings struggle to improve EPC ratings, and what can help

Improving commercial Energy Performance Certificate (EPC) ratings is becoming a strategic priority for organisations managing property portfolios and compliance risk.

With proposed changes to Minimum Energy Efficiency Standards and increasing scrutiny of non domestic building performance, many businesses are now reassessing EPC exposure across their estates.

Yet understanding which building features are holding performance back, and what changes might realistically improve an EPC rating, is not always straightforward.

To support this early stage learning process, Team Energy has created a Commercial EPC Rating Improvement Calculator, an online tool designed to help businesses explore how EPC ratings are influenced and where improvement opportunities may lie.

According to research by the British Property Federation (BPF), who examined energy efficiency of commercial buildings across seven major cities across the UK, 83% of buildings fall below the EPC rating required to meet the proposed 2030 regulations.

Typical building characteristics, such as age, construction, fabric, building services and controls, can affect overall EPC performance. By using simplified, high level inputs, the calculator provides indicative insights into the factors that commonly drive EPC outcomes, helping organisations identify which areas are most likely to benefit from targeted improvements.

For example, a two storey office building built before 1980, with solid walls, mixed glazing and an average roof construction, may achieve a low EPC rating such as a G based on its current specifications. Using the calculator, businesses can see which simple improvements could influence performance, including:

• Upgrading to LED lighting and introducing occupancy or daylight controls where appropriate.Improving building controls, such as time scheduling, zoning and system optimisation, to reduce unnecessary run hours.

• Assessing the feasibility of roof insulation upgrades, often one of the most impactful fabric improvements.

• Considering glazing enhancements or secondary measures like draught proofing or solar control film, depending on building constraints.

Importantly, the EPC Rating Improvement Calculator is intended as an informative planning aid, rather than a compliance tool. It does not produce a legally valid EPC or replace a regulated assessment, which must always be undertaken by an accredited assessor using government approved methodologies such as SBEM. Instead, it is designed to support early conversations, internal engagement and more informed decision making around energy efficiency investment.

The calculator is particularly relevant for estates and facilities teams, sustainability and energy managers, and property and finance teams assessing portfolio performance, refurbishment options or future Minimum Energy Efficiency Standards (MEES) risk. By improving understanding of how EPC ratings are shaped, it helps organisations approach improvement planning with greater clarity and confidence.

‘EPC ratings are often viewed as a pass or fail compliance issue,’ said Graham Paul, service delivery director, Team Energy.

‘In reality, they reflect a combination of building fabric, services and controls that organisations can influence, but only if they understand how those elements interact. The calculator is designed to support that early understanding, before formal assessments are commissioned.’

Developed by Team Energy’s in-house energy consultants, the calculator draws on extensive experience delivering commercial EPC assessments across a wide range of UK non domestic buildings. It provides businesses with a practical starting point, turning EPC ratings from a compliance challenge into a clearer pathway for improvement and long term planning.