Which code expression refers to a building primarily for production or processing purposes?

The expression that accurately refers to a building primarily for production or processing purposes is the term "industrial building." Industrial buildings are specifically designed and utilized for manufacturing, processing, warehouse operations, and similar activities that involve heavy machinery or large-scale production processes. These structures often feature open spaces, high ceilings, and specialized loading and unloading facilities to accommodate the operational needs of industries.

In contrast, commercial buildings are primarily for business activities like retail or office space, assembly buildings are designed for gatherings of large groups of people (such as theaters or conference halls), and residential buildings are intended for living quarters, such as apartments or houses. This distinction highlights why "industrial building" is the correct term for structures focused on production or processing.