For this dimensional check only, use these specified limits: net clear opening area at least 5.0 square feet, clear height at least 24 inches and clear width at least 20 inches. The actual openable portion is 30 inches wide by 24 inches high; the rough opening is 34 by 30 inches. Which finding follows from these data?
- AThe clear height is below the stated 24-inch minimum
- BThe opening fails because the stated 5.0-square-foot limit must be replaced with 5.7
- The net clear area is 5.0 square feet and both stated clear dimensions are met
- DThe net clear opening area is 7.08 square feet
Where to look it up
Explicit exercise assumptions; not a universal code requirement.
Why C is correct
Use the openable dimensions: 30 × 24 = 720 square inches, and 720 / 144 = 5.0 square feet. Height equals the stated minimum; width exceeds it. Rough-opening area is not net clear area. These three checks do not establish sill-height, operation, location or overall escape-opening compliance.