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Recycled wood

If recycled wood is being used to produce wood chip the same wood fuel standards apply  - see Wood Chip Standards (hyperlink to Wood Chip)for more detail.  Two key differences to note are:

  • Different Class/Grade of Recycled Wood between EN Standard and UK Recycling Classifications:
  • If you are using chip from recycled wood it is important to note that your RHI Emissions Certificate specifies the type or Property Class, of wood permitted to be used (see table below).

It is vital to note that recycled wood which has been classified as 'Grade A' under the UK wood recycling classifications, under the EN standard is classified as Class B2. This is a source of much misunderstanding in the UK at present. Such recycled wood can only be used in a boiler with an emission certificate which permits Class B2 wood to be burned.

Property Classes of wood chip (EN14961-1)





  • Whole trees (without roots)
  • Stemwood
  • Untreated wood residues (eg. Sawmill chips)
  • Logging residues

As A1

As A1 + A2 plus:

  • Stumps and roots
  • Bark
  • 'Arb' wood

As A1, A2, B1 plus:

  • Used wood


Max ash 1.0%



Max ash 1.5%


Max ash 3.0%


Max ash 3.0%

For more information on using recycled wood click here.