What’s the Difference Between NFPA 13R and NFPA 13?

by Dean Dalvit, AIA, PE on October 5, 2017

While we typically have a fire sprinkler consultant on the design team for our projects, there are some key things that Architects must know about the systems that can influence design. The NFPA (National Fire Protection Association) has a variety of requirements for different types of projects. This post specifically discusses projects with sleeping areas such as residential, healthcare, hospitality or dormitory types of buildings.


NFPA 13 is a “fully sprinkled” system where NFPA13R is a “partially sprinkled” – a watered down version of the full NFPA13, pardon the pun. Note that the fire protection industry regularly uses the term “sprinklered” which has always struck me as grammatically incorrect, so I prefer to use the term “sprinkled”. You will see both terms throughout the building industry.

The first question is: Where can NFPA13R be used?

While there are always exceptions to the rule, and you should always consult your Architect, fire protection consultant or building official, NFPA13R can typically be used in most hotels and motels, apartment buildings, townhomes and condominiums 4 stories or less, and larger single family homes (most single family homes would actually qualify for an even more reduced requirement in NFPA13D). Meanwhile, the full NFPA13 would be used in hospital resident rooms, nursing homes, dormitory style housing, and multi-story residential over 4 stories.

Why is this important? Because NFPA13 requirements can add significant cost for additional protection that is not required by NFPA13R. In a 13R building, attics, closets and bathrooms typically do not have to be sprinkled. 13R also allows for a lower level of water discharge than 13, which results in smaller pipe sizes. 13R also requires a shorter water supply duration than 13, which can reduce the need for storage or pumps.

In most cases, you can avoid sprinkling floor and roof cavity space in a 13 system if the cavities are filled (typically with insulation). This can result in significant cost savings, but there are a lot of details involved and things to look out for. Especially if you are mixing uses, like multifamily over commercial retail or office, or podium buildings with structured parking.

If you have any concerns, please contact us and we would be happy to help you with your project!


{ 8 comments… read them below or add one }

Dean Dalvit March 13, 2019 at 2:33 pm

Sean – thanks for your question. You won’t actually be able to tell the difference between NFPA13 and 13R by looking at the riser or equipment, unless you can determine a flowrate by looking at a pipe size. The difference is really in the areas required to be sprinkled. So, if you have heads in concealed spaces like attics, or places like storage rooms, then you likely have a 13 system where a 13R system would not sprinkle those spaces. All other equipment will generally appear the same. Pumps often accompany a 13 system, but not always and 13R system could require a pump if the available pressures are low at the site. So you can’t tell from that either. Best bet is to check out the attic space for sprinkler heads…or better yet, have a fire protection contractor or engineer come out and assess what you have. Because depending on the age of the building, it may not fully comply with today’s standards for 13 or 13R anyway. I hope that helps.

Sean March 13, 2019 at 11:24 am

How do you tell if an existing building has an NFPA 13 or 13R system? Is there something printed on the riser?

Dean Dalvit October 2, 2017 at 6:17 am

Prakash, I’m not sure that I understand your question, however all technical questions regarding your actual system installation should be approved by your local jurisdiction having authority. This is especially important if you are not using a trained professional contractor to install the system. Best of luck with your project!

prakash October 2, 2017 at 4:38 am

is it required by pas valave in sure test drain for zone control valve in 3 floor residential villa with domestic water pump and water tank ?

Dean Dalvit April 3, 2017 at 5:01 am

At first blush, your project sounds like it should be a 13R classification. However, local jurisdictions and their fire departments have complete authority to set additional requirements, so only a proper code analysis for your specific project in the context of your local jurisdiction could confirm that. We can provide that service for you if you need, so just let us know if you need any assistance with that. Thanks!

Celine March 28, 2017 at 1:44 pm

I am still a bit confuse on when to use NFPA 13 and 13R. We are planning to build a residential building : dormitory style, because rooms won’t be individually equipped with cooking facilities. The building will have 3 story and 100 rooms total. Which NFPA should be considered in this case : 13 or 13R?

Dean Dalvit October 13, 2016 at 3:03 pm

Generally, yes. Though you would need to confirm the specific system specs with the installer to make sure it is compliant with 13, 13R or 13D.

Bo October 13, 2016 at 2:31 pm

Could all systems 13, 13R and 13 D have dry sprinklers as part of the system in ourdoor covered areas?

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