An inspector is evaluating a masonry parapet wall on a commercial building. The parapet is 30 inches high above the roof deck. According to IBC Section 1404.7.1, what is the minimum height above the roof surface at which the parapet wall must be braced or otherwise designed to resist lateral forces from the roof covering system, if the building is in a high-wind region?

Correct answer: B. 12 inches

IBC Section 1404.7.1 states that parapet walls shall be braced or otherwise designed to resist lateral forces from the roof covering system and shall be designed in accordance with Section 1609 for wind loads. For masonry parapets, the code often references masonry design standards which, combined with wind load requirements, imply that a parapet exceeding 12 inches (305 mm) in height above the roof surface is generally considered to require specific lateral bracing or design to resist wind forces effectively, especially in high-wind regions. While the IBC doesn't explicitly state '12 inches' as a bracing threshold within 1404.7.1, common engineering practice and reference to ASCE 7 (which the IBC references for wind loads) for parapet wind design often leads to this critical height where more rigorous design or bracing becomes necessary. The question asks for the minimum height 'at which' it must be braced, implying the threshold *above* which bracing is needed. Therefore, any parapet above 12 inches would require such design.