Which units are used to express the maximum area protected by the sprinkler riser?

• A. Only square feet
• B. Only square meters
• C. Hectares
• D. Square feet and square meters

Answer: (D)

In NFPA 13R, the area a sprinkler riser protects is a surface area, so it can be reported in the unit system that the project uses. The standard allows either square feet (US customary) or square meters (metric), so both units are acceptable depending on the jurisdiction and documentation. That’s why the best answer is that the maximum area can be expressed in square feet and square meters. Representing the area in hectares isn’t appropriate for typical residential riser zones, and limiting the expression to only one unit would ignore common practice in different regions.