Display Energy Certificates (DEC)

Is your organisation required by law to display a Display Energy Certificate (DEC)? Our registered DEC Assessors can guide you through the entire process with clarity and compliance.

Who must comply?
Public Sector Buildings > 250m²OR Private Sector Buildings> 500m² Visisted Frequently by the public

Legal Obligation

What Is a Display Energy Certificate (DEC)?

A Display Energy Certificate (DEC) is a document that shows how energy efficient a public building is. The aim of a DEC is to encourage public building owners to improve energy efficiency by displaying their energy performance.

The following buildings must comply:

Public Sector
  • Public Sector Buildings larger than 250m²
Private Sector
  • Buildings not occupied by a public body, but are still frequently visited by the public with a total useful floor area of greater than 500m²

Our Approach

How can I get a DEC?

Our team of experienced, registered DEC Assessors will guide you through every step of the certification process. When you work with us, you can expect a clear, efficient, and supportive experience from start to finish.

1

Confirm the building requires a DEC

We will confirm if your building requires a DEC under EU energy-performance regulations

2

Engage with one of our SEAI registered DEC assessors

Only SEAI registered DEC assessors can produce valid certificates using SEAI’s official DEC calculation tool.

3

Provide data

You will need to provide us with 12 months of energy data. We will collect meter readings and/or energy bills for all fuels. If data is incomplete, our experienced assessors can make estimates.

4

Assessment & Benchmarking

The assessor calculates the operational rating and compares it to national benchmarks for the building type, climate, and usage patterns.

5

Certified Upload & Display

The assessor uploads the DEC to SEAI. The building owner must display it prominently and renew it every year.

Why Choose TEA

25+ Years Delivering Ireland's Energy Transition

Tipperary Energy Agency is a not-for-profit social enterprise founded in 1998. We have been at the forefront of energy efficiency and retrofit in Ireland ever since, working with local authorities, communities, businesses, and the public sector across the country.

25+

Years of Experience

Over two decades supporting Ireland's transition to sustainable energy use.

40+

European Projects

Successfully completed more than 40 national and EU research and demonstration projects.

€1.4M

Savings Delivered

Helped Tipperary County Council alone achieve over €1.4 million in energy cost savings.

SEAI

Registered Auditors

Our auditors are SEAI-registered Certified Energy Managers (CEMs), meeting all statutory requirements under SI 426.

Common Questions

Frequently Asked Questions

What will I be asked to provide to the DEC Assessor?

You will need to provide 12 consecutive months of energy‑use data for the building, along with some basic building information. A DEC Assessor will request:

  • Electricity bills - all meters, including landlord and tenant meters
  • Heating fuel bills- gas, oil, biomass, district heating, LPG, etc.
  • Meter readings - if bills don’t align to exact dates
  • Floor area details - treated floor area, zones if applicable
  • Operating hours for the building
  • Any sub‑metering information (if available)
  • Previous DEC (if one exists)
How long will a DEC Assessment take?

Once the required information is gathered by our DEC assessors and the onsite inspection is completed, it typically takes X days for the full process to be complete and the Certificate uploaded to the SEAI.

How often am I required to get a DEC Assessment?

You must renew your DEC annually.

What could happen if I don't comply?

A DEC is a legal requirement for certain buildings. SEAI has been increasingly active in pursuing compliance, and large enterprises are now required to notify SEAI of their compliance status. Non-compliant organisations face legal exposure and reputational risk. Contact us for a free obligation check.

What is the difference between a DEC and a BER?

A Display Energy Certificate (DEC) is based on the building’s actual, measured energy consumption, covering both regulated and unregulated energy uses. In contrast, a Building Energy Rating (BER) is calculated from the building’s predicted energy performance and includes only regulated energy.

Regulated energy is energy that is essential to the buildings core function and typically includes heating, cooling, ventilation systems, hot water production and fixed lighting. Unregulated energy is energy use that is not controlled by building regulations and depends on occupant behaviour, equipment choices and operational patterns.

Ready to Check Your Obligation?

Think your building needs a DEC Assessment? Get in touch today for a no-obligation conversation.