Display Energy Certificate (DEC)

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What is a DEC?

A Display Energy Certificate is a document required for buildings that are occupied by a public authority and are frequently visited by the public.

Depending on the size of the building DECs are either valid for 1 year or 10 years:

  • Architects drawings/site plans and elevations
  • Construction details
  • Planned building services.

What is the DEC validity?

  • 1 year for buildings over 1,000m²
  • 10 years for buildings between 250m² and 1,000m²

It must be publicly displayed and is based on actual energy consumption, unlike EPCs, which are based on predicted performance.

EPC vs DEC – Key Differences?

EPC

DEC

Required for all new, sold, or let properties Required for public buildings frequently visited by the public
Based on predicted energy consumption Based on actual energy consumption
Valid for 10 years Validity varies (1 or 10 years)

How do we help?

With over 20 years of experience, our team delivers accurate, cost-effective SBEM assessments for projects ranging from multi-storey office blocks to veterinary clinics.

We provide:

  • Dynamic Simulation Modelling (DSM) for advanced, detailed analysis
  • Clear guidance on achieving compliance with minimal design changes
  • Liaison with Building Control and Planners if needed

Site visits (where required) to verify building services, fabric, and gather photographic evidence for EPC lodgement.

What we need from you:

  • Site plans and elevations
  • Fabric and glazing details
  • Building services and lighting specifications