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IFC 903.3.1.2 NFPA 13R sprinkler systems - Code Insight

jar546

jar546

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The Code Says:

903.3.1.2 NFPA 13R sprinkler systems.
​

Automatic sprinkler systems in Group R occupancies shall be permitted to be installed throughout in accordance with NFPA 13R where the Group R occupancy meets all of the following conditions:
  1. 1.Four stories or less above grade plane.
  2. 2.For other than Group R-2 occupancies, the floor level of the highest story is 30 feet (9144 mm) or less above the lowest level of fire department vehicle access.
    For Group R-2 occupancies, the roof assembly is less than 45 feet (13 716 mm) above the lowest level of fire department vehicle access. The height of the roof assembly shall be determined by measuring the distance from the lowest required fire vehicle access road surface adjacent to the building to the eave of the highest pitched roof, the intersection of the highest roof to the exterior wall, or the top of the highest parapet, whichever yields the greatest distance.
  3. 3.The floor level of the lowest story is 30 feet (9144 mm) or less below the lowest level of fire department vehicle access.
The number of stories of Group R occupancies constructed in accordance with Sections 510.2 and 510.4 of the International Building Code shall be measured from grade plane.

Insight into this IFC code section:

The provided insights from the code hearings detail the reasoning behind proposed revisions to the 2021 International Fire Code concerning NFPA 13R sprinkler systems in Group R occupancies. This discussion appears to address a significant and practical concern about the operational realities and architectural configurations commonly found in multifamily residential buildings. Here are some key points and their potential implications:

  1. Adjustment of Height Limits:
    • The proposal to increase the height limit from 30 feet to 35 feet for the floor level of the highest and lowest stories relative to the fire department vehicle access addresses a practical issue in modern construction. Many contemporary building designs, especially those with mixed-use elements or higher floor-to-ceiling requirements, would naturally exceed the previous 30-foot limit, thus rendering the NFPA 13R system unusable under old regulations, despite its intended purpose for buildings up to four stories.
    • By adjusting the limit to 35 feet, the code would better accommodate typical building practices and designs without compromising safety, making NFPA 13R systems more applicable and maintaining their intended benefit for fire safety in low to mid-rise residential structures.
  2. Consideration of Building and Access Road Elevations:
    • The measurement of building height from the lowest level of fire department vehicle access (potentially up to 150 feet away from the building) rather than from the adjacent grade can significantly impact compliance. This factor is crucial for understanding the practical challenges in implementing the code, as variations in terrain and site layout can make a substantial difference in meeting the height requirements.
  3. Broader Implications for Fire Safety and Code Compliance:
    • The 2016 NFPA Journal findings support the effectiveness of NFPA 13R systems in protecting lives and reducing property damage, which underpins the rationale for expanding their applicability to more buildings.
    • The debate over the height limit also reflects a deeper consideration of how fire safety codes intersect with building design and urban development. The code's flexibility in accommodating realistic building heights without compromising safety standards is essential for ensuring its broad acceptance and implementation.
  4. Economic Considerations:
    • The discussion around the economic impact of shifting from NFPA 13R to NFPA 13 systems highlights important considerations about housing affordability. The increased costs associated with NFPA 13 systems, due to more extensive sprinkler coverage and other technical requirements, could have a significant impact on construction costs and, consequently, on housing affordability.
  5. Committee Actions and Industry Feedback:
    • The committee's decision to disapprove the proposal based on previous discussions and the absence of compelling new evidence or changed circumstances since the last code cycle indicates a cautious approach to code amendments. This conservatism ensures that changes are made based on solid evidence and broad consensus, reflecting a balance between innovation in fire safety and stability in code regulations.
This thorough examination of practical, economic, and technical issues related to the NFPA 13R systems in the building code hearings illustrates the complexity of code development and the need for careful consideration of a wide range of factors to ensure codes are both effective and realistic.
 
If I understand it correctly, 13R was created to make sprinklers more affordable in multi-family construction (R-2) versus a traditional NFPA-13 system. Basically, it allowed the use of plastic piping. For the few places that require sprinklers in new one- and two-family construction, they came up with 13D which makes it even cheaper. A 13D system is not isolated from the domestic supply and is typically installed using the same PEX that supplies the house. The installs I have seen branch off at the supply (no separate shutoff allowed) and the sprinkler side will terminate at a toilet. The periodic use of the toilet keeps water moving through that branch preventing stagnation.

I think 2010 was the first CA code cycle that used ICC as a model code instead of the Uniform Building Code, and the first instance of a CA Residential Code. From what I gather, people freaked out about this and threw a fit when this requirement was imposed. "I'll never build another house" type of thing, but that didn't last long. Now it's just normal, nobody even blinks at it. It seems like every code cycle there's a few new things that people have a fit over, then they accept and move on.
 
IMHO the 30 foot requirement was a way for the fire code committee to amend the building code. Below is what should have been addressed by the building code committee if the fire people had issues with it

903.3.1.2 NFPA 13R sprinkler systems.
The number of stories of Group R occupancies constructed in accordance with Sections 510.2 and 510.4 shall be measured from the horizontal assembly creating separate buildings.

2021 International Building Code

Revise as follows:

[F]903.3.1.2NFPA 13R sprinkler systems.

Automatic sprinkler systems in Group R occupancies shall be permitted to be installed throughout in accordance with NFPA 13R where the Group R occupancy meets all of the following conditions:

1.Four stories or fewer above grade plane.
2.The floor level of the highest story is 35 feet (10668 mm) or less above the lowest level of fire department vehicle access.
3.The floor level of the lowest story is 35 feet (10668 mm) or less below the lowest level of fire department vehicle access.
The number of stories of Group R occupancies constructed in accordance with Sections 510.2 and 510.4 shall be measured from grade plane.

Reason:

During the previous code development cycle, an issue of significant concern was rectified with respect to NFPA 13R sprinklers in Group R occupancies in podium-style buildings and allowance for as many as four stories up to 60’ in height above grade to be constructed on top of the horizontal building separation. However, while continuing to allow for NFPA 13R systems in four story Group R occupancies, the height limit from fire department vehicle access to the floor level of the highest story was changed to only 30’. In most cases, this height limit will not allow for NFPA 13R sprinklers in a four-story apartment building.

According to feedback from contractors, developers, and design professionals, typical height of floor assembly framing in multifamily buildings is slightly less than twelve inches. A four-story apartment building with 8’-6” ceiling heights and the necessary 8” to 12” foundation exposure above grade, would exceed this 30’ limit. Likewise, a very common mixed use building type of three stories of residential occupancy above ground level retail space would also exceed the 30’ limit. The current 30’ limit is at the very low end of fourth-story floor level height and offers little flexibility for floor-to-ceiling heights greater than 8’-0”. With the current 30’ limitation, NFPA 13R sprinkler systems are essentially limited to three-story buildings: The NFPA 13R standard was specifically created to permit these systems in buildings up to four stories. This proposal will allow the use of NFPA 13R sprinkler systems as envisioned by the standard.

It is also important to understand that the floor level measurement is not taken from the grade adjacent to the building but from the lowest level of fire department vehicle access, which can be up to 150 feet away. The difference in elevation over that distance can be significant, further limiting the number of buildings which can meet this section. Below is an example of a 4-story multifamily building. The 4th floor is at a height of 32' above grade. However, the dimension used as the threshold for a 13R system increases where the lowest level of fire department vehicle access is below the level of grade at the building.



The dimension of 35’ was selected as the limit because it allows more flexibility for building design and floor-to-ceiling height while still remaining well within the 75’ reach of typical fire truck ladders. It is also significantly lower than the 60’ height limit which had been in place prior to the code change in 2021.

NFPA 13R systems have been extremely effective in protecting human lives as well as preventing significant property damage from fire in low-rise residential buildings since the NFPA 13R Standard was first published in 1989. A 2016 issue of the NFPA Journal published the findings of a workshop attended by subject matter experts that focused on the adequacy of 13R sprinklers. Overarching conclusions were 1) that major fires in 13R-protected buildings were the exception – not the rule and 2) that there was not sufficient evidence to indicate that 13R sprinklers have not been effective in protecting human life and reducing property damage. To quote the June 2016 NFPA Report describing the outcomes of the workshop:

  • “NFPA 13R/13D are effective standards that reduces loss of life and building damage due to a fire event.”
  • “To consider or make any changes to NFPA 13R/13D, better (more refined) data needs to be identified as well as collected on a consistent basis. A national database that describes fire events with information on building type/codes would assist in making intelligent changes to any sprinkler standards.”


Essentially limiting the use of NFPA 13R sprinkler systems to Group R buildings three-stories or less does not recognize other significant changes in the codes in recent cycles that offer increased fire protection. Furthermore, there may be some unintended consequences with respect to the current language. Recent cycles have seen changes such as sprinkler requirements for balconies in buildings where 13R sprinklers are used, increased attic protection if it is not sprinklered such as construction of the attic using fire retardant wood or non-combustible materials, and the recent 2021 requirement for special inspections of sealing fire penetrations and draft stopping. All of these ancillary provisions have increased fire protection and stringency of the fire code. Furthermore, by reducing the use of NFPA 13R systems in R-2 occupancies, requirements for sprinkler protection of balconies in these buildings have also been reduced – historically, an issue of significant concern. By extending requirements for NFPA 13 sprinklers in R-2 occupancies, sprinkler requirements for balconies are fewer or non-existent when compared to the absolute mandate of sprinklers on balconies for NFPA 13R systems through the IBC.

Census data reports that of the 13,000 multifamily buildings completed in 2019, more than 10,000 (77%) of these buildings were four stories or less. By reducing the percentage of multifamily buildings where NFPA 13R sprinklers are permitted, the code language as it currently stands will significantly impact housing affordability. The National Multifamily Housing Council estimates that moving from NFPA 13R to NFPA 13 sprinkler systems would carry an incremental installed cost increase of approximately $1.00/sq. ft. to $2.00/sq. ft. of overall building area on average across the US.

NFPA 13R sprinklers are a very effective means of assuring life safety and property protection in Group R buildings four stories and less while maintaining housing affordability. An increase in height to 35’ above or below the lowest level of fire department vehicle access is reasonable and modest and can easily be reached by the typical fire truck ladder.’ This proposal recognizes the long-standing effectiveness of 13R life safety systems, which have been allowed since the early years of the I-codes as well as the legacy codes.

Cost Impact:

The code change proposal will decrease the cost of construction

Costs associated with requirements for attic protection in NFPA 13 systems not only includes the additional sprinklers and piping but also costs associated with increased hydraulic demand and water supply as well as necessary freeze protection in cold and even moderate climates. Greater density and spacing of sprinklers, larger pipe diameter, sprinklers in concealed spaces, and especially, requirements for attic protection (with some exceptions) all contribute to the added cost. This cost increase does not include the final cost with markup to the building owner or the potential need to add a fire pump in the NFPA 13 system. Moving from a 13R system to a 13 system for a $9,342,688, four-story, 48-unit apartment building increased construction costs by $102,255 or a little over $2,100/unit. (Home Innovation Research Labs, Cost Analysis of Proposed Group A Code Changes (2018-2019 ICC Code Development Cycle) – October 2018). This would have a substantial impact on both tenant rental rates and owner-occupied units. The detailed cost analysis is shown below.
 
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