When Fully Sprinklered Isn’t

Both building and fire codes require a building to be “fully sprinklered” for multiple reasons. Certain occupancy types, such as residential (Group R) or hazardous materials (Group H) occupancies are always required to be fully sprinklered. Many other occupancy types are required to be fully sprinklered when over a certain area, located a certain distance above/below grade, and/or based on occupant load. In Massachusetts, there are specific instances where the Massachusetts General Laws require full sprinkler protection. Fully sprinklering a building can also give certain benefits in design and construction such as increased height and area, longer egress travel distances, reduction in ratings for fire barriers, and elimination of certain fire alarm components. For all these conditions, the International Building Code (903.3.1.1) requires that sprinklers be installed throughout in accordance with the proper NFPA sprinkler standard – be it NFPA 13, 13R, or 13D – but there are exceptions. When can you call a building “fully sprinklered” when sprinklers really are not installed everywhere?

The first set of locations are those from the building code (IBC 903.3.1.1.1):

1. Rooms where application of water causes a serious life or fire hazard
2. Rooms where sprinklers are not desirable because of contents, where approved by the fire code official (such as rooms for storage of water-reactive materials)
3. Generator and transformer rooms separated with 2-hour rated construction
4. Rooms that are noncombustible with wholly noncombustible contents
5. Fire service access elevator machine rooms and machinery spaces
6. Machine rooms and spaces, control rooms and spaces associated with occupant evacuation elevators
7. Certain bathrooms less than 55 square feet in R-1, R-2, and R-3 occupancies

The next set of locations are provided by NFPA 13, Standard for the Installation of Sprinkler Systems. For this discussion, we are using the 2013 edition as it is the edition currently adopted and in use in Massachusetts. Newer editions have slightly different criteria (and different locations within the standard itself). These locations are only for NFPA 13 sprinkler systems, and do not include the locations where sprinklers can be omitted which are identified in NFPA 13R, Standard for the Installation of Sprinkler Systems in Low-Rise Residential Occupancies or NFPA 13D, Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes. Both NFPA 13R and NFPA 13D have additional locations – such as attics and bathrooms less than 55 square feet – where sprinklers are not required.

1. Noncombustible concealed spaces with minimal combustible loading
2. Concealed spaces of noncombustible and limited combustible construction with limited access and not permitting occupancy or storage of combustibles
3. Certain spaces above ceilings within combustible construction
4. Concealed spaces filled with noncombustible insulation
5. Concealed spaces over rooms less than 55 square feet
6. Concealed spaces where the exposed materials are constructed entirely of fire retardant-treated wood
7. Noncombustible concealed spaces where the heat content of the facing and substate of the insulation does not exceed 1,000 Btu per square foot
8. Combustible soffits, eaves, overhangs, and decorative frame elements not over 4 feet in width, that are draftstopped into volumes less than 160 cubic feet, separated from the building with no openings or unprotected penetrations into the building, and with no storage beneath
9. Noncombustible or limited-combustible, nonaccessible vertical duct, mechanical, or electrical shafts
10. Noncombustible exit corridors where the exterior walls are at least 50 percent open
11. Closets in dwelling units and hotels that are less than 24 square feet and the ceilings are noncombustible or limited combustible, or 6 square feet in hospital patient rooms.
12. Two-hour rated electrical rooms for dry type electrical equipment only with no combustible storage
13. Inside or underneath portable furniture
14. Inside electrical equipment, mechanical equipment or air handling units not intended for occupancy

Additionally, in Massachusetts, there are several specific locations where sprinklers are not required:

1. Certain spaces in telecommunications buildings that are provided with smoke detection and separated from the remainder of the building with 1-hour fire barriers and 2-hour floors.
2. Noncombustible and limited combustible concealed spaces and plenums containing electrical, data, communications, and other cables as permitted by 527 CMR [plenum-rated cable].
3. Transformer vaults meeting certain requirements
4. Machine rooms of traction/drum hydraulic elevators, elevator hoistways, and elevator pits; sprinklers are also expressly prohibited from these spaces by 524 CMR Massachusetts Board of Elevator Regulations

It should be noted that Massachusetts specific exemptions or prohibitions on sprinkler installation in certain rooms may not be applicable in buildings subject to federal regulations; such as healthcare facilities regulated by Centers for Medicare & Medicaid Services (CMS) requirements, federal buildings where PBS-P100 Facilities Standards for Public Buildings Service, or Department of Defense Unified Facilities Criteria requirements are utilized. In those cases, the most restrictive requirements would apply and conflicts between the codes should be reviewed on a case-by-case basis.

Given the above criteria, there are many locations where sprinklers do not have to be installed for a building to be considered “fully sprinklered.” These locations depend on a number of factors with the design and intended use of the building and its spaces and can be a subject to the discretion of both the Registered Design Professional and Authority Having Jurisdiction involved. If you have questions as to whether sprinklers are required in a particular location, please contact our office at 617-500-7633 or info@crcfire.com to speak with our team.