The weight of structural wood in a structure or module is the total mass in kilograms or pounds of all the wood in its load-bearing, wind-resisting, and form-giving skeletal framework. This does not include wood used in removable non-load-bearing walls, decorative wood elements which are not integral to the frame, wood flooring, wood in windows, non-load-bearing wood facades, or other non-structural wood. It does include wood joists used to support permanent walls, floors, and roofs, as well as structural columns, lintels, and beams. This includes elements both above ground and below ground, including the foundations.

A material quantity taken from a bill of quantities or structural drawings may describe specified work. The source should distinguish that quantity from one established for completed work.

The material counts only where it does structural work. Reinforcement in a non-structural screed, cladding hung on a frame and decorative timber are outside these fields even though they are the same material.

Where a structure was extended or partly rebuilt, the figure belongs to whichever scope the source measured. A weight for the original building and one for the building today are different numbers.