There is a level of inefficiency in transporting pre-assembled panels. Also, if panels must be moved greater distances, they may require additional reinforcement and structure.
Trucking and transport limitations usually make it much more expensive to work with panels over 8.5 feet in width. Length limitations also must be considered.
Some panelizers cannot make panels larger than 9 to 10 feet in width.
The manufacturer must consider standard container dimensions if wall assemblies are going to be shipped.