Residential Building Inspector B1General Administration, Legal, and EnforcementMedium
A residential building inspector is reviewing the definitions section of the 2021 IRC. The term 'Story' is defined. According to the IRC, what is the highest number of stories above grade plane that a typical residential dwelling is permitted to have without additional fire-protection provisions?
- A2 stories
- B5 stories
- C3 stories
- D4 stories
Show answer & explanationAnswer & explanation
Correct answer: C. 3 stories
The 2021 IRC (Section R302.1, Exception 4 for R302.13) generally limits residential dwellings to three stories above grade plane without requiring additional fire-protection provisions like automatic sprinkler systems, especially when considering the attic space as a story for fire protection purposes or when dealing with larger or more complex structures.
Why the other options are wrong
- A. While common, it's not the maximum allowed without additional provisions.
- B. Five stories would definitely exceed the typical residential limits without significant fire-protection systems.
- D. Four stories would typically trigger requirements for an automatic sprinkler system or other enhanced fire-protection provisions under the IRC.
Max Stories Above Grade Plane (IRC)
The 2021 IRC generally permits a maximum of three stories above grade plane for typical residential dwellings without requiring additional fire-protection provisions, such as an automatic sprinkler system.
- IRC R302.1, Exception 4 for R302.13.
- Limits are for typical residential.
- Exceeding 3 stories triggers additional fire protection.
Memory trick: Three's the Limit, for IRC's simple fire safety.