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  • Jerry Schultz, P.E.


My last blog spoke about high-piled permits and the potential to correct deficiencies in a sprinkler system due to occupancy changes. It seems natural for me to move this into a discussion on retroactivity, and how can one get a sprinkler system updated to reflect more current requirements when it was designed to meet an earlier code or standard. Before I proceed, let me say that I believe in the concept of the code of record and that we should not be attempting to bring all sprinkler systems up to current standards. I believe that the concept of retroactivity is defined adequately by NFPA and recognize that there are certain items that need to be applied retroactively and others that were designed to a given standard based on the state of knowledge when it was designed and installed and may remain that way. It is a judgment call on the part of the code official or the consulting engineer that has to be judiciously applied. I address retroactivity here for discussion purposes but recognize that I don’t have the answers. It really comes down to what you are comfortable with.

NFPA has long recognized that fire protection levels may change based on new information and data coming forward whether it’s from fire loss experience, fire tests, or other evidence that changes might be necessary. However, that does not mean we should have to review our existing sprinkler system every 3 years and bring it up to the current standard. The Retroactivity requirement appears in Chapter 1 and states:

1.4 Retroactivity.

The provisions of this standard reflect a consensus of what is necessary to provide an acceptable degree of protection from the hazards addressed in this standard at the time the standard was issued.


Unless otherwise specified, the provisions of this standard shall not apply to facilities, equipment, structures, or installations that existed or were approved for construction or installation prior to the effective date of the standard. Where specified, the provisions of this standard shall be retroactive.


In those cases where the authority having jurisdiction determines that the existing situation presents an unacceptable degree of risk, the authority having jurisdiction shall be permitted to apply retroactively any portions of this standard deemed appropriate.


The retroactive requirements of this standard shall be permitted to be modified if their application clearly would be impractical in the judgment of the authority having jurisdiction, and only where it is clearly evident that a reasonable degree of safety is provided.

Just as an aside, I find it interesting that these four sections are found in numerous codes and standards that NFPA publishes but NFPA 72, National Fire Alarm and Signaling Code modified the requirements and addressed retroactivity a little bit differently. They stated the following:

1.4 Retroactivity.


Unless otherwise noted, it is not intended that the provisions of this document be applied to facilities, equipment, structures, or installations that were existing or approved for construction or installation prior to the effective date of the document.


In those cases where it is determined by the authority having jurisdiction that the existing situation involves a distinct hazard to life or property, retroactive application of the provisions of this document shall be permitted.

I see the difference but have a difficult time understanding why there is a difference.

Staying with the NFPA 13 definition, it is obvious that it was not the intent to require the continual upgrade of an existing system HOWEVER, they give a lot of discretionary authority/responsibility to the authority having jurisdiction (AHJ). By NFPA 13, if the AHJ believes that the existing situation presents an unacceptable degree of risk, they can elect to have the building/system upgraded to meet the new requirements of the standard. Note that NFPA 72 mentions a “distinct hazard to life or property” but basically grants the same power to the AHJ.

What presents an unacceptable degree of risk is a judgment call. Two examples are obvious in my mind. In the 1996 edition, NFPA 13 added a requirement that sprinklers in a light hazard occupancy are required to be quick response. Prior to that edition of the standard, sprinklers in a light hazard occupancy were standard response sprinklers (the quick response sprinkler was not available for much of that time). Do you, if you were the AHJ, feel that all sprinklers in a system installed prior to 1996 should be changed out because the lack of quick response sprinklers represents “an unacceptable degree of risk”?

Another example is that prior to the 2016 edition of NFPA 13, expanded exposed Group A plastics in racks was outside the scope of Chapter 17, and therefore outside the scope of NFPA 13. Does this mean that people were not storing expanded exposed Group A plastics? There were no couches, upholstered furniture, coolers, mattresses on racks in warehouses? Perhaps the building was just not being sprinklered.

Figure Decision Tree.

Of course not. The protection scheme was being developed by fire protection engineers, insurance companies, contractors and others and accepted by the AHJ. In 2016, protection criteria for rack storage of expanded, exposed Group A plastics appeared in the standard for the first time. In 2019, additional protection schemes were added to the standard giving the designer a lot more flexibility. I ask you again, do you, as the AHJ, believe that the protection scheme provided for an expanded, exposed Group A plastic in a rack should be retroactively upgraded to the protection scheme outlined in the newest edition of NFPA 13?

I have my opinion on each of these scenarios, but I really believe that you have to make up your own mind. You need to identify what is an unacceptable degree of risk, and that is going to vary depending upon a variety of contributing factors. For the quick response scenario, let’s modify the scenario a little bit and say that we are dealing with a memory care facility where residents are not capable of evacuation, and we recognize that the residential sprinkler is now available. Does this change your opinion? Let’s add the fact that the memory care facility is providing excellent care to residents but is barely getting by and the cost of the change out would impact them greatly. Where are you now?

Let’s go one step further and review the Life Safety Code (NFPA 101), specifically Section (6) of the 2021 edition of the code. This section states:

Standard-response sprinklers shall be permitted to be continued to be used in approved existing sprinkler systems where quick-response and residential sprinklers were not listed for use in such locations at the time of installation.

What is interesting is that I had to go to the Life Safety Code to find this requirement.

For the exposed, expanded Group A plastic scenario, let’s say that the current design uses k5.6 in-rack sprinklers discharging at 15 gpm and the overhead system is designed for a 0.24 gpm density over the most remote 2400 square feet. The commodity is 18 foot high foam mattresses standing on end in racks to a height of 18 feet on end and wrapped in plastic with no longitudinal flue and transverse flues every 10 feet. Do you now require an upgrade to the newest criteria?

The last issue is an issue that I don’t understand and relates to Section 1.4.1. This section states:


Unless otherwise specified, the provisions of this standard shall not apply to facilities, equipment, structures, or installations that existed or were approved for construction or installation prior to the effective date of the standard. Where specified, the provisions of this standard shall be retroactive.

I have reviewed NFPA 13 by searching for the word “existing” and have identified retroactive requirements. Certain sections that appear to have a solid basis for a retroactive classification are not being pushed as retroactive. An example is found in ESFR sprinklers in a 40’ high building. This scenario was allowed to be protected with a k14 sprinkler in the 2010 edition (and earlier) but is not allowed in the 2013 (and later) editions. The committee was informed that in certain instances, the k14 sprinkler did not work in a 40 foot high building. The 2013 NFPA 13 Handbook states:

The original ESFR criteria allowed K-14 ESFR sprinklers to protect ceilings 40 ft (12.2 m) in height without in-rack sprinklers. However, subsequent fire tests have shown that, given a certain combination of fire ignition points between sprinklers and 40 ft (12.2 m) ceilings, the K-14 ESFR sprinkler might not provide fire suppression for all storage commodities.

So we know that “given a certain combination”, the k14 ESFR sprinkler will not work and the committee was so concerned that the design option was removed from the standard BUT you are not required by NFPA 13 to change the sprinkler if it was installed under the 2010 standard. Is the committee stating that this sprinkler is acceptable for an existing installation and perhaps although not a “suppression” sprinkler it still functions as a “control” mode sprinkler. Or is the committee stating that whether or not the sprinkler should be changed out is strictly up to you based on your research? In my opinion, it is a complicated decision because the tests that led to the decision to not allow this sprinkler in a new installation are not available (if someone can locate them, please let me know).

To go back, the decision to apply the standard retroactively is not an easy decision but it is a critical one. This is the stuff that keeps all of us up at night. Good luck!

If you have any comment, questions or want to talk with me, please email me at

My next blog will discuss Automatic Storage/Retrieval Systems specifically identifying NFPA 13 and FM Data Sheet 8-34. This may end up being a two part discussion.


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