What is the term for a vertical section through the narrow width of a building?

The term for a vertical section through the narrow width of a building is known as a transverse section. This type of section is crucial in architectural and engineering contexts as it provides a view that cuts across the structure, allowing for an examination of internal layouts, structural components, and spatial relationships within the building. In contrast, a longitudinal section would show a slice taken along the longer dimension of the building, providing a different perspective. Section elevation, on the other hand, represents how the structure appears from a particular vantage point, and while it may give a sense of height, it does not focus specifically on the cross-sectional view that a transverse section offers. Thus, the definition that aligns with the concept of cutting through the narrow width and showing the arrangement within is, indeed, the transverse section.