Which of the following best defines total interior wall length?

Total interior wall length is defined as the cumulative length of all the walls that segment the interior spaces of a building. This includes the walls of individual rooms but does not take into account the exterior walls or only the structural load-bearing walls.

Choosing the total length for specific rooms combined captures this definition accurately. It reflects how interior walls define the usable spaces within a structure and their collective contribution to planning, design, and calculations for purposes such as materials estimation and cost analysis.

In contrast, the other choices limit the definition by focusing on specific types of walls or measures that do not represent the complete picture of interior wall measurement. For instance, reference to only supporting walls or exterior walls does not encompass all the wall lengths necessary for a full assessment of a building's interior configuration. Meanwhile, using an average wall length would not accurately reflect the total length, as it disregards the variability and specificity of individual room walls.