Bored holes not greater than 60 percent of the depth of the stud are permitted in what type of partitions?

Bored holes not greater than 60 percent of the depth of the stud are permitted in nonbearing partitions because these types of walls are not designed to support significant loads. Nonbearing partitions primarily serve as separators between spaces and do not bear the weight of the structure above them. Therefore, they can accommodate modifications like bored holes without compromising structural integrity, as there is less concern regarding load-bearing capacity.

In contrast, bearing partitions must maintain their strength due to the loads they support, and therefore, the allowances for modifications such as bored holes are more restricted to ensure safety and stability. Additionally, exterior walls typically require a higher level of structural integrity to withstand external forces, and double studs provide added support for areas where load may be concentrated, thus having stricter guidelines regarding alterations.