A parapet is not required on an exterior wall under which condition?

A parapet is typically a low wall extending above the roofline of a building, serving several purposes including safety, fire protection, and structural integrity. In considering the conditions under which a parapet is not required on an exterior wall, it's important to recognize that each of the conditions presented supports the idea that a parapet may not be needed.

When a wall is not required to be fire-resistance rated, there is less concern regarding the potential for fire spread from the roof area. This can diminish the necessity for a parapet as a protective barrier.

Additionally, if the building has a relatively small maximum area of 1,000 square feet on any floor, it may fall into a category that is less likely to need added fire safety features, which further justifies the absence of a parapet.

The use of noncombustible materials for a roof also plays a role. Structures built with noncombustible materials tend to have a reduced risk of fire, thus lowering the justification for the presence of parapets, which are often intended to contain fires or protect against their spread.

Since all provided conditions can independently justify the lack of requirement for a parapet, the correct response indicates that any of them being true can exempt a building from