Partially sprinklered school

[kurt999]

• IBC 2018
• Illinois location
• K-12, Group "E"
• Type IIB construction of new addition
• Two-story building addition, 10,500 SF / floor
• New addition to be fully sprinklered.
• Existing school buildings are not sprinklered -- one is type IIB, one is type VB.

School addition is to be placed between two existing and separate campus buildings. Each existing building is between 10 and 30 feet of separation, but will be connected by small new corridor "connectors".

Given the size of the new floors, I believe it would be possible to use fire separation walls and not include sprinklers within the new building.
That said, the school has directed us to fully sprinkler the new addition. The existing buildings will remain unsprinklered.

To keep my question as simple as possible: my confusion has to do with the interface of a new, fully sprinklered building connected to an existing unsprinklered building -- mainly as it relates to fire areas and fire walls.
Without sprinklers, schools are regularly divided into the 12,000 SF max fire areas for "E" and the associated 2-hour fire walls. In my case, what needs to happen at the new-to-old, sprinklered to unsprinklered building connections? Do I still need the 2-hour fire wall?

Thank you in advance.

 

[RLGA]

Use Section 3104 for the "corridor connectors" and treat each building separately using the exterior fire resistance requirements based on the fire separation distance from an imaginary lot line between the buildings.

 

[Yankee Chronicler]

RLGA beat me to it. 3104 Pedestrian walkways is the answer. Using that section, the walkway doesn't belong to either of the buildings it connects.

 

[Tim Mailloux]

but then do they truly have to be separate buildings with separate electrical and water services serving each?

 

[kurt999]

Thanks much for the responses.

So the enclosed walkways and tunnels approach is interesting. It does appears to require fire barriers at each end of the enclosed walkways, and the 3104.5.1.1 requirements are not insignificant:

3104.5.1 ​

Pedestrian walkways shall be separated from the interior of the building by not less than 2- hour fire barriers constructed in accordance with Section 707 and Sections 3104.5.1.1 through 3104.5.1.3.

3104.5.1.1 ​

Exterior walls of buildings connected to pedestrian walkways shall be 2-hour fire resistance rated. This protection shall extend not less than 10 feet (3048 mm) in every direction surrounding the perimeter of the pedestrian walkway.

So, for the existing buildings to be connected -- am I reading this correctly: -- we'd need to add 2-hour fire barrier protection to the existing building exterior surfaces adjacent to the enclosed walkways -- for 10 feet on each side and then 10 feet above the walkway?

Thank you in advance.

 

[RLGA]

Look at Section 3104.5.2. If you sprinkler the walkways and the buildings are more than 10 feet apart, then you do not need the fire barriers--just resist the passage of smoke or provide a glass assembly meeting the criteria of Section 3104.5.2.2.

 

[kurt999]

RLGA -- thanks for the additional input -- very helpful. So I think this is the logic you are applying:

3104.2 Separate structures.
Buildings connected by pedestrian walkways or tunnels shall be considered to be separate structures.
Exceptions:
1.Buildings that are on the same lot and considered as portions of a single building in accordance with Section 503.1.2.

3104.5 Connections of pedestrian walkways to buildings.
The connection of a pedestrian walkway to a building shall comply with Section 3104.5.1, 3104.5.2, 3104.5.3 or 3104.5.4.
Exception: Buildings that are on the same lot and considered as portions of a single building in accordance with Section 503.1.2.

503.1.2 Buildings on same lot.
Two or more buildings on the same lot shall be regulated as separate buildings or shall be considered as portions of one building where the building height, number of stories of each building and the aggregate building area of the buildings are within the limitations specified in Sections 504 and 506. The provisions of this code applicable to the aggregate building shall be applicable to each building.

So per these sections, the buildings are considered separate, and then per Table 602 require no fire resistance for the exterior walls based on fire separation distance.

​

 

[RLGA]

The exception to Section 3104.5 actually would not apply because you want to consider them as separate buildings per Section 503.1.2 and not as portions of a single building, to which the exception is for.

 

[kurt999]

The exception to Section 3104.5 actually would not apply because you want to consider them as separate buildings per Section 503.1.2 and not as portions of a single building, to which the exception is for.

The way I wrote that with the highlights is kind of muddled now that I read it again -- but I did catch your point and appreciate the direction.

Thank you again.

 

[RLGA]

Just a word of caution. Some plans examiners do not understand the concept of Section 3104. They may try to apply fire separation distance criteria to the pedestrian walkways.

I had a client with a school project who was adding a building similar to your circumstance, but they had existing pedestrian walkways to which the new building would be connected. The project was in Phoenix, and the pedestrian walkways are just canopies with no walls--only columns. The plans examiner wanted the existing walkways protected because of the distance between the new building and the existing walkway, which runs parallel to one of the new building's exterior walls. The walkway was non-combustible (i.e., 100% all steel) with no concealed space and absolutely no fire load (unless you consider the students). He would not budge--even after I forwarded a code opinion I received from ICC. The architect ended up moving the building by a couple of additional feet away from the pedestrian walkway to satiate the plans examiner rather than continue hitting our heads against the wall.

 

[kurt999]

Just a word of caution. Some plans examiners do not understand the concept of Section 3104. They may try to apply fire separation distance criteria to the pedestrian walkways.

I had a client with a school project who was adding a building similar to your circumstance, but they had existing pedestrian walkways to which the new building would be connected. The project was in Phoenix, and the pedestrian walkways are just canopies with no walls--only columns. The plans examiner wanted the existing walkways protected because of the distance between the new building and the existing walkway, which runs parallel to one of the new building's exterior walls. The walkway was non-combustible (i.e., 100% all steel) with no concealed space and absolutely no fire load (unless you consider the students). He would not budge--even after I forwarded a code opinion I received from ICC. The architect ended up moving the building by a couple of additional feet away from the pedestrian walkway to satiate the plans examiner rather than continue hitting our heads against the wall.

That's good advice. As I almost always do, I've sent my preliminary proposed code direction to the building official for his review. I'll post his yay or nay response for anyone curious.

 

[BayPointArchitect]

Just a word of caution. Some plans examiners do not understand the concept of Section 3104. They may try to apply fire separation distance criteria to the pedestrian walkways.

I had a client with a school project who was adding a building similar to your circumstance, but they had existing pedestrian walkways to which the new building would be connected. The project was in Phoenix, and the pedestrian walkways are just canopies with no walls--only columns. The plans examiner wanted the existing walkways protected because of the distance between the new building and the existing walkway, which runs parallel to one of the new building's exterior walls. The walkway was non-combustible (i.e., 100% all steel) with no concealed space and absolutely no fire load (unless you consider the students). He would not budge--even after I forwarded a code opinion I received from ICC. The architect ended up moving the building by a couple of additional feet away from the pedestrian walkway to satiate the plans examiner rather than continue hitting our heads against the wall.

I know a plans examiner like that.