Commercial EPCs for Non-Domestic Buildings

Why EPC Ratings Matter

Commercial EPCs are increasingly used as an indicator of asset risk, compliance and future investment requirements.

An EPC may be required when a building is sold, leased or newly constructed, but many organisations now use EPC ratings to support wider asset management decisions, refurbishment planning and decarbonisation programmes.

Property owners, investors and asset managers often review EPC ratings to:

• Understand potential MEES risks
• Support acquisition and disposal decisions
• Plan improvements towards EPC B
• Prioritise capital investment
• Inform refurbishment and decarbonisation strategies

For many organisations, the EPC is no longer simply a compliance document. It is often the starting point for understanding future regulatory requirements and sustainability objectives.

What We Do

KJ Tait undertakes commercial EPC assessments for non-domestic buildings across England, Scotland and Wales.

Our assessments are completed using the approved methodology for the building type and jurisdiction. We focus on gathering evidence that materially affects the EPC calculation, helping to reduce reliance on default assumptions where supporting documentation is available.

We review:

• Building fabric
• Heating systems
• Cooling systems
• Ventilation systems
• Building controls
• Lighting installations
• Renewable technologies
• Available operation and maintenance documentation

Following assessment, the EPC is lodged on the appropriate national register.

Where clients are considering future compliance requirements, refurbishment projects or EPC improvement opportunities, we can also provide wider advice on EPC B pathways, MEES compliance and building performance.

When Is a Commercial EPC Required?

Commercial EPCs are typically required when a building is sold, leased to a new tenant or newly constructed.

Certain refurbishment and fit-out projects may also trigger EPC requirements where a building is altered for separate occupation and fixed building services are modified.

Requirements vary between jurisdictions and exemptions may apply depending on the building type, occupancy and proposed transaction.

Common reasons clients commission commercial EPCs include:

• Property sales
• New lease transactions
• Building completion and handover
• Acquisition due diligence
• Portfolio reviews
• MEES compliance reviews
• EPC B planning and improvement strategies

EPC Levels (3, 4 and 5)

Non-domestic EPC assessments are commonly grouped into Levels 3, 4 and 5. The level refers to the complexity of the building and the assessment methodology used, rather than the EPC rating itself.

Levels 3 and 4 are typically assessed using the Simplified Building Energy Model (SBEM). Level 5 assessments use Dynamic Simulation Modelling (DSM), which creates a detailed three-dimensional model of a building and simulates performance over time.

Level 5 EPCs are required for some complex buildings where simplified assessment methods cannot accurately represent building services, controls or operating characteristics.

DSM can also be used for simpler buildings. For this reason, KJ Tait can assess any type of non-domestic building using Level 5 methodology where appropriate.

Where a building would normally be assessed using SBEM, we explain the assumptions adopted and identify any evidence that could materially affect confidence in the result.

EPCs and Building Performance

A commercial EPC provides a standardised assessment of a building's energy performance using approved methodologies and assumptions. It is an important compliance tool, but it should not be confused with actual energy consumption.

Two buildings with similar EPC ratings can perform very differently in operation depending on occupancy patterns, operating hours, controls, maintenance and how the building is managed.

For this reason, many organisations use EPCs alongside wider building performance assessments when reviewing asset performance, refurbishment opportunities and decarbonisation strategies.

As Chartered Building Services Engineers, KJ Tait's expertise extends beyond EPC assessment. Our team also provides energy modelling, operational energy analysis, building performance reviews, NABERS UK consultancy and decarbonisation planning.

This broader understanding of how buildings operate helps clients interpret EPC results, identify improvement opportunities and make more informed investment decisions.

EPC B Pathways

Many building owners, investors and asset managers are reviewing how their assets may achieve EPC B and improve resilience against future regulatory change.

An EPC recommendation report can provide useful guidance, but it does not usually deliver a complete strategy for achieving a target rating.

KJ Tait's EPC B Pathway service helps clients understand:

• Current EPC performance
• Potential improvement measures
• Indicative costs and sequencing
• MEES and compliance considerations
• Potential impact on future EPC ratings
• Links between EPC performance and wider decarbonisation objectives

Our approach focuses on identifying practical improvement opportunities that align with asset plans, refurbishment programmes and wider investment objectives.

For many organisations, achieving EPC B is not simply about improving a certificate. It is about making informed decisions that balance compliance, capital expenditure, building performance and long-term value.