What is the minimum allowable stud size in nominal inches for conventional wall framing?

The minimum allowable stud size for conventional wall framing is typically 2 inches. This size, which corresponds to 2x4 lumber, is commonly used in residential and light commercial construction for framing interior and exterior walls. The nominal dimensions relate to the lumber's designation, wherein a 2x4 stud is actually smaller in measurement when finished, but the nominal size describes its intended use and structural capability.

Using 2-inch studs allows for adequate load-bearing capacity while still being manageable for construction purposes. It is the standard in the industry, contributing to both the structural integrity and thermal performance of wall assemblies. The use of larger stud sizes, such as 3 inches or 4 inches, is generally reserved for specialized applications—where increased load-bearing capacity or space for insulation might be necessary. In conventional framing scenarios, however, the 2-inch size stands as the baseline for wall frameworks.