Five-Story Hotel and the 13R Proposal
An architect proposes NFPA 13R for a new five-story, 72,000 ft² hotel (96 guest rooms) in Raleigh. The building is 63 ft 4 in. above grade plane, Type III-A construction, with an attached 2,400 ft² restaurant and a 1,500 ft² assembly room on the first floor. The contractor's 13R bid omits sprinklers from guest bathrooms, closets under 24 ft², the elevator machine room, electrical rooms, and the combustible concealed space above the fourth-floor ceiling. The restaurant has a Type I grease duct and a separate kitchen hood suppression system. The local fire marshal reviews the permit set and tells the owner that the design basis is wrong. The owner asks whether the 13R bid can be value-engineered to keep the cost, or whether the whole building must be NFPA 13.
1. Is NFPA 13R permitted as the design basis for this hotel? Identify the controlling limit and explain how the restaurant and assembly room affect the answer.
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No. NFPA 13R is a residential standard limited to residential occupancies up to and including four stories in height. This building is five stories, so the residential portion already exceeds the 13R scope; the architect's bid does not create an allowance.
The restaurant and assembly room are not residential occupancies. NFPA 13R cannot be the sole basis for those areas. In a mixed-occupancy building the designer must either protect the whole building under NFPA 13 or use code-permitted fire separations and apply NFPA 13 to the nonresidential portions. Because the hotel portion still fails the four-story limit, separation does not rescue the 13R bid.
The correct path is to redesign the entire building to NFPA 13, then compare the 13R omissions against NFPA 13 requirements. Value engineering can adjust materials or layout, but it cannot change the adopted design standard.
2. The 13R bid omitted sprinklers in guest bathrooms, small closets, the elevator machine room, electrical rooms, and the concealed ceiling space. How should each omission be evaluated under NFPA 13?
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Treat the 13R omissions as a checklist, not as automatic NFPA 13 omissions. For each location, find the specific NFPA 13 omission criterion and document it.
- Guest bathrooms: 13R often permits omission in small bathrooms; NFPA 13 has narrower allowances. Protect unless the room meets the exact size, construction, and combustibility limits in the adopted edition.
- Closets under 24 ft²: do not carry the 13R threshold over. Check NFPA 13 for the closet omission rule; if the closet contains combustibles or is not of limited-combustible construction, protect it.
- Elevator machine room: check the NFPA 13 provisions for elevator machine rooms, hoistways, and pits. Omission is not automatic; noncombustible hydraulic fluid and equipment type matter.
- Electrical rooms: NFPA 13 has specific conditions for omitting sprinklers in electrical equipment rooms. Verify the room contains only allowed equipment and is dedicated to that use; otherwise protect.
- Concealed ceiling space: 13R permits omission in some concealed spaces; NFPA 13 requires protection of combustible concealed spaces unless the space meets a specific noncombustible or limited-combustible exception. The combustible space above the fourth floor is a likely required area.
The designer should mark each omission on the drawings with the code basis, not just delete heads.
3. Does the kitchen hood suppression system remove the need for sprinklers in the restaurant? Explain the coordination.
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No. The hood system protects the cooking hood, filters, and duct; it is not a building sprinkler system. It does not protect the restaurant seating, storage, ceiling, or adjacent rooms, and it does not satisfy the NFPA 13 design basis.
The two systems must be coordinated: NFPA 96 governs the commercial cooking suppression and duct; NFPA 13 governs the building sprinklers. The designer must check the NFPA 13 rules for commercial cooking areas and for the grease duct, and must show on the drawings where sprinklers are required, omitted, or affected by the hood system. The presence of the hood system may affect the sprinkler layout and the protection of the hood/duct area, but it does not eliminate general sprinkler coverage.