Separate Fire Areas and Unlimited Areas

[jl3]

Hi All,

We have a natatorium addition (A3, IIB, one story, 15,000 SF) to an existing rec center (A3, IIB, one story, 33,000 SF) which would put us over the allowable area, so we've provided a 2 hour separation between existing and new to create separate fire areas, which we're assuming is possible. I would first like to confirm that we're correct in doing this and also if the separation is actually 2 hour (according to 707.3.10) or if there's some possibility of it being 1 hour.

For various design and egress reasons, we were also looking at the possibility of unlimited area per 507.6 so that we could do away with the fire separation, but I'm a bit unclear on the 60 ft clear dimension as there's an existing school to the east. A consultant of ours thought this might be possible given that there are unlimited area options for both A3 and E and that the 60 ft surrounding area could encompass both the school and rec center.

The image below shows the condition. The red dotted area is the existing rec center, green box is our new addition; Orange area is the existing school, yellow dotted area is offset 60 ft. The blue is our property line. There is also a 3hr separation between the rec center and school where they adjoin, the school shares the gym in the rec center which is the area directly north of our addition.

Located in CO, IBC 2018.

 

[classicT]

Fire barriers do not create separate buildings. To create separate buildings, you must utilize fire walls. Per Table 706.4, you need a 3-hr fire wall.

And as a reminder, fire walls have to be structurally independent and allow collapse of the structure on either side.

 

[cda]

Welcome

You do know your first question is supposed to be easy!!!

Give it a few days for great answers

 

[cda]

Do you meet all the parameters for unlimited?



an article to check

http://www.specsandcodes.com/articles/code_corner/The Code Corner No. 27 - Fire Areas.pdf

 

[cda]

One more read


https://www.thebuildingcodeforum.com/forum/threads/unlimited-building.27824/#post-212137

 

[jl3]

Fire barriers do not create separate buildings. To create separate buildings, you must utilize fire walls. Per Table 706.4, you need a 3-hr fire wall.

And as a reminder, fire walls have to be structurally independent and allow collapse of the structure on either side.

Do they need to be considered separate buildings to establish separate fire areas? I guess our understanding was that we could create separate fire areas to get around the square footage limit, but if we actually have to construct them as separate buildings (which I suppose they technically would be minus penetrations/openings) then I understand the need for the fire walls.

 

[jl3]

Do you meet all the parameters for unlimited?



an article to check

http://www.specsandcodes.com/articles/code_corner/The Code Corner No. 27 - Fire Areas.pdf

That's what we're unsure of, we're good with the first 2 requirements, but the 60 ft surrounding area requirement makes me think of a building in the middle of a lot with nothing around it... I guess we're wondering that if both our building and the adjacent school meet all the other unlimited area requirements, minus the 60 ft requirement individually, that they could be seen as a 'single' building and share the 60 ft requirement. Though I understand this might not be possible given that they're separate properties, even though they are connected.

 

[classicT]

Do they need to be considered separate buildings to establish separate fire areas? I guess our understanding was that we could create separate fire areas to get around the square footage limit, but if we actually have to construct them as separate buildings (which I suppose they technically would be minus penetrations/openings) then I understand the need for the fire walls.

The limits noted in Chapter 5 are limits for the size of buildings, not fire areas. Fire areas control when fire protection systems (i.e. alarms, sprinklers, etc.) are required.

As others have indicated, if you are up against the allowable building area per Ch. 5, then you can either attempt to go as an unlimited area building, or may use fire walls.

 

[cda]

That's what we're unsure of, we're good with the first 2 requirements, but the 60 ft surrounding area requirement makes me think of a building in the middle of a lot with nothing around it... I guess we're wondering that if both our building and the adjacent school meet all the other unlimited area requirements, minus the 60 ft requirement individually, that they could be seen as a 'single' building and share the 60 ft requirement. Though I understand this might not be possible given that they're separate properties, even though they are connected.

Read 507.2 for where to measure to

So 507.2 , do you meet the 60 feet clear??

 

[jl3]

Thanks all, this helps greatly. It would seem that we don't meet the 60 ft open requirement based on what 507.2 outline and we'll need a 2 hr (per footnote (a) of 706.4) fire wall between the existing rec center and our new addition.

 

[cda]

Thanks all, this helps greatly. It would seem that we don't meet the 60 ft open requirement based on what 507.2 outline and we'll need a 2 hr (per footnote (a) of 706.4) fire wall between the existing rec center and our new addition.

Can you rate openings where needed to meet the 60?

 

[jl3]

Can you rate openings where needed to meet the 60?

We can, but would that also apply to the existing portion of our building where we don't meet that 60 ft requirement?

 

[classicT]

507.2.1 Reduced Open Space

The public ways or yards of 60 feet (18 288 mm) in width required in Sections 507.3, 507.4, 507.5, 507.6 and 507.12 shall be permitted to be reduced to not less than 40 feet (12 192 mm) in width provided all of the following requirements are met:

1. The reduced width shall not be allowed for more than 75 percent of the perimeter of the building.
2. The exterior walls facing the reduced width shall have a fire-resistance rating of not less than 3 hours.
3. Openings in the exterior walls facing the reduced width shall have opening protectives with a fire protection rating of not less than 3 hours.