Sprinkler Systems

Sprinkler Systems in Part 9 Buildings

DESIGN STANDARDS FOR RESIDENTIAL PART 9 SPRINKLER SYSTEMS

The 2024 BC Building Code has changed the wording to allow NFPA 13D systems in townhouses and duplexes with secondary suites as per the excerpt below:

3.2.5.12.
3) Instead of the requirements of Sentence (1), NFPA 13D, "Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes" is permitted to be used for the design, construction and installation of an automatic sprinkler system installed

a) in a building of residential occupancy throughout that contains not more than two dwelling units, 

b) in a building of care occupancy, provided 

i) it contains not more than two suites of care occupancy, 

ii) it has not more than five residents throughout, and 

iii) a 30-minute water supply demand can be met , and 

c) in a building of residential occupancy throughout that contains more than two dwelling units, provided 

i) except for a secondary suite, no dwelling unit is located above another dwelling unit, 

ii) all suites are separated by a vertical fire separation having a fire-resistance rating of not less than 1 h that provides continuous protection from the top of the footing to the underside of the roof deck, with any space between the top of the wall and the roof deck tightly filled with mineral wool or noncombustible material, 

iii) each dwelling unit has its own sprinkler water supply provided in accordance with NFPA 13D, "Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes," 

iv) a passive purge sprinkler system design is used as described in NFPA 13D, "Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes," and 

v) where the sprinkler system is taken into consideration for the reduction of limiting distance, all rooms, including closets, bathrooms and attached garages, that adjoin an exposing building face are sprinklered, notwithstanding any exemption stated in NFPA 13D, "Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes." (See Note A-3.2.5.12.(2).) 

WHEN IS A SPRINKLER SYSTEM REQUIRED FOR PART 9 RESDIENTIAL BUILDINGS

The BC Building Code typically does not require sprinkler systems for residential buildings that are three storeys and under (e.g. houses, townhomes, low-rise residences). However, there are other provisions in the BC Building Code which may make the installation of sprinklers advantageous to builders and designers, such as increased glazing and reduced fire ratings for structural components.

While the Building Code may not require sprinklers systems, local bylaws or water supply (fire flow) requirements may trigger the requirement for sprinkler systems. Presently, a professional engineer is required to calculate the needed fire flow (NFF) using either the Fire Underwriters Survey (FUS) method or the Insurance Services Office (ISO) method for fire flow calculation, these calculation will determine whether the municipal water supply at the site is sufficient to enable emergency response personnel to control fire growth. The BC Government has provided the Factsheet: Fire Sprinklers as a summary of the requirements.

BC Building Code 2024 A-3.2.5.7.(1) Water Supply. The intent of Sentence 3.2.5.7.(1) is that an adequate water supply for firefighting be readily available and of sufficient volume and pressure to enable emergency response personnel to control fire growth so as to enable the safe evacuation of occupants and the conduct of search and rescue operations, prevent the fire from spreading to adjacent buildings, and provide a limited measure of property protection.

The water supply requirements for buildings containing internal fire suppression systems, including sprinkler systems and standpipe systems, are contained in specific standards referenced in the Code. Compliance with the referenced standard, including any variations made by this Code, is deemed to satisfy the intent of Sentence 3.2.5.7.(1). However, it will be necessary to verify that an adequate source of water is available at the building site to meet the required quantities and pressures.

For a building with no internal fire suppression system, the determination of the minimum requirements applicable to the water supply for firefighting is relevant mainly to building sites not serviced by municipal water supply systems. For building sites serviced by municipal water supply systems, where the water supply duration is not a concern, water supply flow rates at minimum pressures is the main focus of this provision. However, where municipal water supply capacities are limited, it may be necessary for buildings to have supplemental water supplies on site or readily available.

The sources of water supply for firefighting purposes may be natural or developed. Natural sources may include ponds, lakes, rivers, streams, bays, creeks, and springs. Developed sources may include aboveground tanks, elevated gravity tanks, cisterns, swimming pools, wells, reservoirs, aqueducts, artesian wells, tankers, hydrants served by a public or private water system, and canals. Consideration should be given to ensuring that water sources will be accessible to fire department equipment under all climatic conditions.

The volume of on-site water supply is dependent on the building size, construction, occupancy, exposure and environmental impact potential, and should be sufficient to allow at least 30 minutes of fire department hose stream use.

For the purposes of calculating adequate water supply requirements for fire fighting, the following documents may be useful:
• Insurance Services Office (ISO), “Needed Fire Flow Guide,”
• NFPA 1142, “Standard on Water Supplies for Suburban and Rural Fire Fighting,” and
• American Water Works Association, “Distribution Requirements for Fire Protection.”

REQUIREMENT FOR REGISTERED PROFESSIONAL DESIGN

In the 2024 BC Building Code, Subsection 2.2.7. Professional Design and Review gives the following as the required scope for Letters of Assurance. Note that only NFPA 13 sprinkler systems require design by a registered professional, not NFPA 13D or NFPA 13R sprinkler systems, therefore a registered professional is not required by the BC Building Code for the design of sprinkler systems in most Part 9 residential buildings. (See also: Are sprinkler systems required to be designed by a registered professional?):

(NOTE: The Vancouver Building Bylaw 2019 requires professional design for NFPA 13, NFPA 13R, and NFPA 13D sprinkler systems)

 2.2.7.1. Application

1) The requirements of this Subsection apply to

a) buildings within the scope of Part 3 of Division B,

b) buildings within the scope of Part 9 of Division B that are designed with common egress systems for the occupants and require the use of firewalls according to Article 1.3.3.4. of Division A, and

c) the following, in respect of buildings within the scope of Part 9 of Division B other than buildings described in Clause (b),

i) structural components that are not within the scope of Part 9 of Division B (See Note A-2.2.7.1.(1)(c)(i).),

ii) geotechnical conditions at building sites that fall outside the scope of Part 9 of Division B,

iii) sprinkler systems designed to NFPA 13, “Installation of Sprinkler Systems”, and

iv) standpipe and hose systems designed to NFPA 14, “Installation of Standpipe and Hose Systems”.

Note A-2.2.7.1.(1)(c)(i) Structural Components. The reference to “structural components of buildings that fall within the scope of Part 4” includes the situation where a building is classified under Part 9 due to its size and occupancy but also contains some structural components (such as beams supporting concentrated loads) which must be designed under Part 4. In this situation only Schedules B and C-B for the structural components are required. Schedule A and Schedules B, C-A and C-B relating to non-structural components are not required.

REVIEW OF NFPA SPRINKLER SYSTEMS

NFPA 13 “Installation of Sprinkler Systems.” Applies to all buildings requiring sprinkler systems other than those provided below as 13D or 13R designs.
NFPA 13R “Installation of Sprinkler Systems in Low-Rise Residential Occupancies”
a) Group C buildings containing no other major occupancy that is not more than 3 storeys in building height and conforms to BCBC 9.10.1.3.
b) In a building of care occupancy with not more than 10 occupants that is not more than 3 storeys in building height and conforms to one of BCBC Articles 3.2.2.42. to 3.2.2.46.
NFPA 13D “Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes”
a) in a building of residential occupancy throughout that contains not more than 2 dwelling units, or
b) in a building of residential occupancy throughout that contains more than 2 dwelling units and meets the other requirements of 3.2.5.12.(3) or
c) in a building of care occupancy, provided i) it contains not more than 2 suites of care occupancy, ii) it has not more than 5 residents throughout, and iii) a 30-minute water supply demand can be met.

This is a summary of the BC Building Code requirements as it pertains to Part 9 buildings only, please refer to BC Building Code 2024 Division B Section 9.10.1.3.(8) and 3.2.5.12. for complete details and requirements

STANDPIPE AND HOSE SYSTEM DESIGN REQUIREMENTS

According to the 2024 BC Building Code a Standpipe System designed to NFPA 14 is required as shown below.

3.2.5.8. Standpipe Systems
1) Except as permitted by Sentence 3.2.5.9.(4), a standpipe system shall be installed in a building that is

a) more than 3 storeys in building height,
b) more than 14 m high measured between grade and the ceiling of the top storey, or
c) not more than 14 m high measured between grade and the ceiling of the top storey but has a building area exceeding the area shown in Table 3.2.5.8. for the applicable building height unless the building is sprinklered throughout.

See also Table 3.2.5.8. (All building sizes requiring standpipes are outside of Part 9)

3.2.5.9.(4) A standpipe need not be installed in a storage garage conforming to Article 3.2.2.90., provided the building is not more than 15 m high.