What is a Display Energy Certificate?

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.

An example of a DEC is shown. It should be displayed in a prominent location in your building.

Requirements for a DEC
w
Public Sector Buildings

larger than 250m²

w
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  

What we do

Our team of SEAI registered DEC assessors will guide you through the process of obtaining a DEC. 

Confirm if the building requires a DEC

Public buildings over 250 m² that are regularly accessed by the public must display a DEC annually, as required under EU energy‑performance regulations.

Confirm if the building requires a DEC

Public buildings over 250 m² that are regularly accessed by the public must display a DEC annually, as required under EU energy‑performance regulations.

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.

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.

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.

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.

Assessment and benchmarking

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

Assessment and benchmarking

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

Certificate upload and display

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

Certificate upload and display

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

Why choose Tipperary Energy Agency?

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.

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

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 €1.4M in energy cost savings.

€1.4M Savings Delivered

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

SEAI Registered Auditors

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

SEAI Registered Auditors

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

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. 

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.

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.

How often am I required to get DEC Assessments?

You must renew your DEC annually.

Speak to an expert

Looking for the right solution for your facility? Contact us today to discuss your needs and see how we can support your goals.