Apply the openable-area ratio in 2024 IMC Section 402.2 to a 250-square-foot bedroom. There are no other qualifying ventilation openings. What minimum total area openable to the outdoors is required by this ratio?
- A5 square feet
- B7 square feet
- 10 square feet
- D12 square feet
Where to look it up
https://www.iccsafe.org/building-safety-journal/bsj-technical/code-corner-2024-international-mechanical-code-chapter-4-ventilation/
Why C is correct
The rule uses 4% of the floor area being ventilated: 250 × 0.04 = 10 square feet of openable area. This is not a universal bedroom window size; only the openable portion counts. The calculation does not determine emergency escape, light or other requirements.