ThermoWoodŽ Concept is an entirety that ensures the technical and ecological quality of products sold under the trademark ThermoWoodŽ. Development of the Concept is part of the long term plan of the International ThermoWood Association to enhance use of thermally modified timber.

ThermoWoodŽ Concept consists of the following sectors:

  1. Patented thermal modification process
    The industry scale ThermoWoodŽ process was developed and patented by VTT Technical Research Centre of Finland.

  2. Registered trademark
    ThermoWoodŽ trademark is owned by the International ThermoWood Association. The trademark is now registered in EU, Switzerland, Canada, USA, Russia, Japan, China, Iran, Australia and New Zealand. Only the member companies of the International ThermoWood Association have the right to use these registered trademarks.

  3. Audited quality control system
    The quality control of ThermoWoodŽ production was developed in cooperation with research laboratories, member companies and Finotrol Oy. Finotrol Oy is also the third party auditor of the quality control system and issues the right to use a FC certification mark.

    The list of ThermoWoodŽ producers that have the right to use the FC certification mark can be found at

    The members that have the right to use FC inspection mark with ThermoWoodŽ product have also the right to use the quality stamp of the International ThermoWood Association.

    Some ThermoWoodŽ producers have the right to use the KOMO certificate of the Dutch testing company SKH.

  4. Life cycle assessment (LCA)
    Life cycle assessment of ThermoWoodŽ is finished. The LCA was carried out by the Imperial College London. Abstract of ThermoWoodŽ LCA is published on the website of the International ThermoWood Association.
  5. Certified raw material
    The FFCS (Finnish Forest Certification System) was developed for Finnish circumstances and it demonstrates reliably how the Finnish certified forests are managed and used. The certification system includes all the essential components for forest certification: requirements for forest management and use and chain of custody verification as well as the qualification criteria for external auditing. The FFCS was accepted by PEFC (Programme for the Endorsement of Forest Certification schemes) forest certification system. The Finnish Forest Certification Council issues the PEFC logo use rights in Finland on the behalf of the PEFC Council. About 90% of sawn wood that is thermally modified in Finland comes from PEFC certified forests. OLB (Origine et Légalité des Bois) is a certification system designed to verify the origin of timber and compliance with legal requirements in forest management and harvesting.

    Information about FFCS and PEFC forest certification systems can be found at

  6. Standardisation
    ThermoWoodŽ product classification was completed in 2003. Two standard treatment classes were introduced. The classes are called Thermo-S and Thermo-D. Information about ThermoWoodŽ classification can be found in the ThermoWoodŽ Handbook, ThermoWoodŽ brochures and website of the International ThermoWood Association.

  7. Continuous research and development activities
    International ThermoWood Association annually allocates resources for topical R&D activities.