Residential sprinklers must be listed unless exceptions apply per guidelines.

• A. Not required.
• B. Always required.
• C. Required only in high-rise buildings.
• D. Required unless exceptions apply per specific guidelines.

Answer: (D)

Residential sprinklers have to be listed by a recognized testing laboratory so you know they’ve been tested and rated for home environments and will perform reliably with typical residential piping and water supply. The statement you’re learning reflects that default requirement: you use listed sprinklers unless the guidelines explicitly allow an exception. Those exceptions aren’t open-ended; they’re limited to specific situations outlined in the guidelines. In practice, unlisted sprinklers aren’t permitted unless an approved guideline exception applies. This isn’t about high-rise only, and it isn’t that listing is optional.