Does CBC 1029 apply to an office building balcony?

[nealderidder]

A colleague and I are having a disagreement about CBC 1029 and where it applies. In particular 1029.3.1 which is a California addition that applies some of the requirements for 300 occupant assembly spaces to spaces with only 100 occupants. The question is, when does any of this section apply to an exterior balcony in an office building?

To illustrate the point, consider an upper level 749 SF exterior balcony in an office building. How many exits (or exit access doors) are required? A multiple choice quiz:

A. One

• Per 303.1.2 the balcony is a "B" occupancy
• OLF for "B" = 150
• 749/150 = 5 occupants
• Per 1006.2.1 one exit is required

B. Two

• Occupant load is based on Use not Occupancy Classification so answer "A" above is bogus.
• OLF for "A" with no furnishings of any kind = 5
• 749/5 = 150 occupants
• Per 1006.2.1 two exits are required

C. Two, One of which leads directly to an exit

• Occupant load is based on Use not Occupancy Classification so answer "A" above is bogus.
• OLF for "A" with no furnishings of any kind = 5
• 749/5 = 150 occupants
• Per 1006.2.1 two exits are required
• Per 1029.3.1 one of the two required MOE shall lead directly to an exit.

D. None of the above


Section 1029 certainly feels like it is written for theatres and big ballrooms. Spaces where large crowds of people are in unfamiliar surroundings and may panic in an emergency. This section is intended to address things like the urge people have to go out the door they came in, ignoring the fact that there are other ways out. Should this apply to a modest size office building balcony? But right there in the first line of 1029.1: A room or space used for assembly purposes... takes away the argument "But this space isn't an Assembly occupancy". The rest of that line says ...that contains seats, tables, displays, equipment or other material shall comply with this section. Which is weird. So if it's a space with nothing in it this section doesn't apply? But yes, of course there will wind up being some tables and chairs in there so I'll let that go.

So if I had a balcony that was 300 x OLF 15 = 4,500 SF. I could maybe see the argument that these 1029 safety measures should apply.

But CA added 1029.3.1 that applies to a 100 occupant space. San Diego often insists we use an OLF of 5 for balconies. This means that a balcony that is (100*5) 500 SF or larger must have some of the same egress features that a 5,000 SF theatre requires, if 1029.3.1 applies.

Note that 1029.3.1 starts with Group A occupancies....that have an occupant load of 100 to 300... That seems like the trump card to me. It specifically says Group A Occupancies. CBC 303.1.2(2) says that an assembly space less than 750 SF is a Group B Occupancy. This is why my answer to the quiz is "B" (my colleague says "C").

What's your answer?



Thank you. Sorry it got a bit long there...

 

[RLGA]

D - None of the above.

1. I would never use an occupant load factor of 5 sq. ft. for an assembly area unless it was queuing space. At most, I would use 7 sq. ft.
2. Section 303.1.2 says that it can be classified as Group B if the area is less than 750 sq. ft., regardless of the occupant load factor used.

 

[nealderidder]

D - None of the above.

1. I would never use an occupant load factor of 5 sq. ft. for an assembly area unless it was queuing space. At most, I would use 7 sq. ft.
2. Section 303.1.2 says that it can be classified as Group B if the area is less than 750 sq. ft., regardless of the occupant load factor used.

Hi Ron. Agreed that an OLF of 5 is wrong in this case.

What do you think of the question about 1029.3.1? Does it apply to an accessory balcony on an office building? 1029.3.1 is one of those CA additions to the code.

 

[Tim Mailloux]

D - None of the above.

1. I would never use an occupant load factor of 5 sq. ft. for an assembly area unless it was queuing space. At most, I would use 7 sq. ft.
2. Section 303.1.2 says that it can be classified as Group B if the area is less than 750 sq. ft., regardless of the occupant load factor used.

Occupancy group and occupant load factors are not related. The Balcony is defiantly group B, but depending on how its going to be used will determine the correct function of space and occupant load factor.

 

[steveray]

Put a table and chairs on it and make it moot.....

 

[JPohling]

Typically in San Diego the plan reviewer will want you to match the occupancy of the area that the balcony is serving. If it is off the open office areas apply "B" if it is off a conference room apply "A". if it qualifies as a B due to SF apply "B"