While traceability and transparency are important, achieving them is challenging in many circumstances.

One major reason is mixing within the supply chain: it is very common for wood to be mixed at different stages of manufacturing and distribution. To take cross-laminated timber as an example, starting at the forest and working down:

  • A logging contractor takes ownership of standing trees after winning a timber sale or is contracted by a landowner to harvest timber. After felling, timber is cut to length, often sorted, and sold to buyers interested in each specific species and grade;
  • In some instances, logs are not sold directly to mills but instead go to concentration yards that buy timber from numerous landowners and/or logging contractors and do further sorting;
  • Sawmills procure logs from a variety of sources (e.g., forest owners, logging contractors, and concentration yards) and deck them in the log yard, sorting by species, grade, and length. Logs are pulled for manufacture into lumber in batches focused on yield or production of target dimensions and grade, often making it difficult to tie an individual board to a specific source;[1]
  • In some cases, sawmills sell lumber (graded lamstock) direct to CLT manufacturers while in others lumber is sold to wholesale distributors who sell whole units (banded or packaged lots) to CLT fabricators or pull material from different units of lumber in inventory to fill an order;
  • CLT manufacturers either custom purchase lamstock for specified projects or buy inventory of lamstock from a number of distributors and sawmills.[2] Units from different suppliers are not often mixed but production rarely tracks input material origin in a way that can be shared with customers.

See full size version

Currently there is no one-size-fits-all approach to cultivating traceability and transparency.

This guidance is intended to provide the foundation for owners and the AEC community to consistently require transparency and traceability in their procurement. This can present some challenges that must be overcome, such as:

  • Requires additional time and planning up front
  • Some pathways require much more effort than others, depending on context (e.g., procurement geography or product-specific considerations)
  • Requirements that add labor or other costs need to add value to the material or otherwise be compensated for, before industry will adopt them
  • Secrecy, resistance and inertia throughout the supply chain – for competitive reasons, it is typical for supply chain actors to closely guard information about their sources

For all these reasons, project teams should be prepared to invest in traceability and transparency, and to reward suppliers for their cooperation, particularly when extraordinary efforts are needed.


[1] Note, however, that mills that focus on cutting higher grade lumber track individual log sources more often than mills focused on high production rates. For this reason, beams and wood used for lamstock offer a better opportunity for projects asking for segregation of logs from specific landowners than do mills cutting for standard dimensional lumber markets.

[2] Custom purchase of lamstock happens more frequently for large custom orders while production from inventory occurs more frequently at mills fulfilling smaller orders and commodity CLT dimensions. Options for custom purchase are often limited to known suppliers to reduce risks.