The standard for the installation of sprinkler systems in residential occupancies up to and including four stories in height is:

• A. NFPA 13
• B. NFPA 13D
• C. NFPA 13R
• D. NFPA 14

Answer: (C)

Residential buildings up to four stories have different design needs than single-family homes or commercial spaces. NFPA 13R is specifically written to address sprinkler systems in those multi-unit or dormitory-type residential occupancies, balancing protection with practical system design for housing. It sets requirements for sprinkler placement, water supply, and system performance that fit smaller, residential-scale buildings without the broader, more demanding criteria found in NFPA 13 for commercial/industrial spaces.

NFPA 13D applies only to one- and two-family dwellings, which are simpler and covered by a separate standard. NFPA 13 covers most non-residential systems and larger or more complex occupancies, with stricter design and installation rules. NFPA 14 governs standpipes, which are not the primary concern for typical residential sprinkler systems. So for residential occupancies up to four stories, NFPA 13R is the appropriate standard.