Fire Alarm - Mixed Occupancy Buildings

Tainted

Senior Member
Location
New York
Occupation
Engineer
If there’s a building that occupies residential and commercial, does this mean there needs to be 2 separate fire alarm control panels isolated from each other dedicated to the occupancy? Or do we need 1 fire alarm control panel for the entire building?
I went to an existing building with 2 existing fire alarm control panels and I was wondering if the 2 fire alarm control panels need to communicate with each other. If so, how?
 

Rock86

Senior Member
Location
new york
Occupation
Electrical Engineer / Electrician
There is a section in the 2020 NYS Fire Code which mentions "mixed" occupancies. I would have to look it up, but depending on how the occupancies are separated may allow for the separation of the two systems. But if they are considered one building, you should have a system that alarms the residents individually, while if there is an event within common space of the building, all occupants should be notified.
Designing of the system comes down to the fire alarm system can handle the programming required.

Are you NYC or NYS? That makes a difference as well.
 

Tainted

Senior Member
Location
New York
Occupation
Engineer
There is a section in the 2020 NYS Fire Code which mentions "mixed" occupancies. I would have to look it up, but depending on how the occupancies are separated may allow for the separation of the two systems. But if they are considered one building, you should have a system that alarms the residents individually, while if there is an event within common space of the building, all occupants should be notified.
Designing of the system comes down to the fire alarm system can handle the programming required.

Are you NYC or NYS? That makes a difference as well.
NYC, I’m assuming if they are seperated by 2 hour rated wall then it would be ok to separate the systems? This is just a guess as I’m not sure
 

Rock86

Senior Member
Location
new york
Occupation
Electrical Engineer / Electrician
One benefit to NYC, if you're wrong, plans & review will let you know. hahaha. I'm not super familiar with NYC Codes. Did a little work down there a few years back, but I am outside of the city.
 

Fire Pro

Member
Location
US
Occupation
Owner/CEO of Fire Pro
If there’s a building that occupies residential and commercial, does this mean there needs to be 2 separate fire alarm control panels isolated from each other dedicated to the occupancy? Or do we need 1 fire alarm control panel for the entire building?
I went to an existing building with 2 existing fire alarm control panels and I was wondering if the 2 fire alarm control panels need to communicate with each other. If so, how?
No there doesn't need 2 different systems/panels, just 1. Generally, you take whichever code is stricter of the 2 occupancies and you design and install the system according to that. You'd have to contact the building owner to find out what happened in that situation, and/or the AHJ.
 

Tainted

Senior Member
Location
New York
Occupation
Engineer
No there doesn't need 2 different systems/panels, just 1. Generally, you take whichever code is stricter of the 2 occupancies and you design and install the system according to that. You'd have to contact the building owner to find out what happened in that situation, and/or the AHJ.
Yea but how would you know which one is stricter? What if they're equally strict? At what point would determining this be not subjective? The building I encountered already has 2 separate fire alarm systems (1 for residential and 1 for commercial) tapped as separate services and I'm not even sure why because it can literally be done with just 1 system.
 

Tainted

Senior Member
Location
New York
Occupation
Engineer
One benefit to NYC, if you're wrong, plans & review will let you know. hahaha. I'm not super familiar with NYC Codes. Did a little work down there a few years back, but I am outside of the city.
Good to know, but I'm still trying to figure out where in the code it says you can have 2 separate fire alarm systems isolated from each other in the same building as long as there is 2 hour fire rated barrier between the 2 occupancies lol.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
Good to know, but I'm still trying to figure out where in the code it says you can have 2 separate fire alarm systems isolated from each other in the same building as long as there is 2 hour fire rated barrier between the 2 occupancies lol.
The first question to answer is does the separation allow you to treat them as two different "buildings"? If yes, then the next question is, do either or both of them require a fire alarm system? Install only where required. If you need a fire alarm for both occupancies then you will be allowed to install only one fire alarm system. FDNY won't let you have two communicator accounts for the same physical address. If the separation is insufficient, then the more strict occupancy applies to the entire building.
 

Tainted

Senior Member
Location
New York
Occupation
Engineer
The first question to answer is does the separation allow you to treat them as two different "buildings"? If yes, then the next question is, do either or both of them require a fire alarm system? Install only where required. If you need a fire alarm for both occupancies then you will be allowed to install only one fire alarm system. FDNY won't let you have two communicator accounts for the same physical address. If the separation is insufficient, then the more strict occupancy applies to the entire building.
I see… How do you know which one is stricter? The two occuancies are R-2 (residential) and group-B (commercial)?
 

Fire Pro

Member
Location
US
Occupation
Owner/CEO of Fire Pro
Yea but how would you know which one is stricter? What if they're equally strict? At what point would determining this be not subjective? The building I encountered already has 2 separate fire alarm systems (1 for residential and 1 for commercial) tapped as separate services and I'm not even sure why because it can literally be done with just 1 system.
You'd know by checking the IBC/IFC but like I said with this having 2 separate systems, that's something either the owner or AHJ can answer, because that sure isn't in any code book.
 

Rock86

Senior Member
Location
new york
Occupation
Electrical Engineer / Electrician
You'd know by checking the IBC/IFC but like I said with this having 2 separate systems, that's something either the owner or AHJ can answer, because that sure isn't in any code book.
Agreed. We evaluate the two systems and compare them to see which requires more.
 

Rock86

Senior Member
Location
new york
Occupation
Electrical Engineer / Electrician
Good to know, but I'm still trying to figure out where in the code it says you can have 2 separate fire alarm systems isolated from each other in the same building as long as there is 2 hour fire rated barrier between the 2 occupancies lol.
I know the code is somewhere. This question came up recently in our office. We had an apartment complex where the one building had three sections of apartments, and we evaluated that because there was a block wall that went from grade through the roof that it became three separate buildings.
 

Strathead

Senior Member
In my experience, Florida and California, you are required to have a fire alarm "system" for each occupancy of a residential facility. 120 volt smoke detectors tied together are a stand alone fire alarm system. If the local code requires monitoring, then you can use a monitor module at each unit.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
I know the code is somewhere. This question came up recently in our office. We had an apartment complex where the one building had three sections of apartments, and we evaluated that because there was a block wall that went from grade through the roof that it became three separate buildings.
Was the block wall part of a UL listed fire-rated assembly? Did any penetrations in the wall comply with the listing?
 
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