FDC for Each Building in Private Fire Water Loop?

1/2/2026

I'm having trouble finding code citations for this, but if a single-owner site with multiple buildings (like a transportation authority property that has multiple separate buildings) has a dedicated fire water loop serving the sprinkler and hydrant water for the site, can they provide FDCs where the fire water ties into the municipal water, and not provide FDCs for the individual building sprinklers?

Or is each sprinkler system required to have its own FDC?

I would imagine that each building with a sprinkler system would still require an FDC, but I can't really find code language about this specific topic.

Thanks in advance.

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10 Comments

Glenn Berger

1/2/2026 08:10:17 am

NFPA 13 "somewhat" requires one FDC for the sprinkler systems within that building. Not one FDC per sprinkler system.

The use of a single FDC for a complex may work to supply the site, but the fire department is still pulling water for their hoses downstream of this connection and will end up starving the sprinkler system of required flow.

Ivan Humberson

1/2/2026 08:12:24 am

It is standard practice to tie the FDC into the sprinkler system on the system side (downstream) of the main sprinkler shut-off valve. That way, should the main shut-off valve be closed for some reason, the fire department can still supply water to the sprinkler system. Therefore, each sprinkler system would need a separate FDC.

Chad

1/2/2026 08:39:31 am

100% this. One broken water main kills all possibility of providing water from a fire engine to ANY/ALL buildings? Unacceptable risk especially for a critical quasi public building. AHJ should be playing the AHJ card on this one.

I don’t have NFPA 1 in front of me but AHJ can compel that from chapter 1/admin rules.

Dave L.

1/2/2026 10:52:48 am

Check NFPA 13, 13, and 24 as applicable; it is very nuanced. For example, each sprinkler system (as defined in Chapter 3 of NFPA 13) is not required to have its own FDC. However, "For multiple systems the fire department connection shall be connected between the supply control valves and the system control valves," which is followed by "...shall not apply where the fire department connection is connected to the underground piping." Each configuration carries with it a varying level of risk, and this, along with access and signage should be discussed with the AHJ. I have had AHJ's allow this, and I have had AHJ's require a separate FDC for each building.

Josh

1/2/2026 08:30:57 am

Campus FDC has been commonly used on projects since I've worked on in multiple states. Some AHJs don't want them, but some do. You're going to run into semantics galore in ways only lawyerly people write when you try to nail this one down. They will hammer home the importance of accessibility, visibility and effective use, typically.

Two big items of importance I see commonly when doing these are making sure to keep control valves to a minimum, eg: don't put PIVs in each run-up to each building's riser if the FDC is upstream. Second, make sure the FDC hydrant is upstream of shutoffs also.

My experience has been that the responding FM is usually the one who will make that call on whether they like it or not.

Mark

1/2/2026 10:03:55 am

Thank you for submitting this question.
We had a similar condition.
Josh, I'm new to this industry, for "effective use", wouldn't requiring an FDC per bldg. make sense? That way, the FD would only pump the bldg that's in an event and not additional structures?

Josh

1/2/2026 11:14:46 am

Not necessarily. If you step back to a broader picture, you can see you're always robbing peter to pay paul no matter how you set it up. You can "steal" from the main in one place or you can steal from it in another place. To effectively utilize an FDC you are needing a hydrant close enough to an FDC to put a truck's pump in there nearby. Charging a loop is not uncommon.

Remember, code only says every sprinkler system must be serviceable, essentially. It seems the committee was intentionally vague here and chose not to explicitly require an FDC per building. I think it's a good choice because the committee is not who has to respond to a fire at 3 AM when it's below freezing in winter. In my opinion, each AHJ/FM is the appropriate decision-maker on how they want an FDC(s) arranged. That is the most critical component of a system and they need to have full control to utilize it the best way they can.

One last tidbit - in my city, the fire marshal does not even allow an attack truck at the building until the engine has been hooked up to the FDC. There are a lot of campus-style FDC setups here and in neighboring towns. It has to be a reasonable design with control valves deliberately placed and properly labeled/located for this to work to start with. You also cannot have disproportionate demand, etc. As is usually the case, the answer is more complex than yes/no and the whole scenario requires thinking.

Jack G

1/2/2026 11:31:45 am

Site fdc s are common. The majority of the time, there is a meter pit/ BFP pit with an fdc after the valving and on the system side water main. Also a separate fire hydrant from the supply ( before the pit valving ) off the city supply mains.
If the hose allowances are calculated properly, the individual system flow is not affected. ( I d use 500 gpm for the site fdc flow, similar to a small pump) Individual building fdc s would need hydrants near them( 100 ft ) to provide the fire department water.

Chad

1/2/2026 01:03:07 pm

The OP stated the water main that feeds the hydrants and sprinkler systems is the same. The FDC distance to hydrants/FDC is irrelevant if that main breaks. You are laying hose and might have to relay pump if distance is an issue. Same as if it was not a campus style system.

However, even if all I have is 500 gal in the tank, at least I can use that to supplement the standpipe while a water supply is established. The 2nd due engine will have another 500, we can get a knock on the fire with 1000 gallons (if not, bigger problem) That is why I would require an FDC on each building.

Jaclyn

1/5/2026 06:17:04 am

As an AHJ, we typically require a city hydrant within 200' of the FDC of each building if there is also a loop present. In the event of a fire, the city hydrant would be used to feed the FDC and the hydrants on the loop would be used for other firefighting needs. The purpose of this is to avoid depleting the sprinkler system water supply to the building.

FDC for Each Building in Private Fire Water Loop?

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