Occupancy Separation

[Examiner]

Given:

Mixed Occupancy building; A-3 and S-1

Two story building but the top floor is much small than the bottom floor. The top floor is not a mezzanine.

Construction Type II-B

Fire suppression system throughout.

The bottom floor has A-3 & some S-1 areas, The S-1 areas as an aggregated total do not equate to more than 10% of the bottom floor’s area.

The top floor is totally S-1 and is under 3,000-sf. Therefore, I think this puts the second floor in the realm of Mixed Occupancy Separation and avoids accessible access to the upper floor. To avoid fire separation I feel that Section 508.3.2 Non-separated occupancies will be the method to use.

If it is a two story building why would Section 403 need to be reviewed?

 

[High Desert]

It's a pointer in case it's a high-rise building. If not, you can disregard it. For what it's worth, you could also have a building designed as nonseparated occupancies and not be required to have sprinklers so you could disregard both 403 and Chapter 9 in that case.

 

[Simonsays]

Review section 403 only if first story is in excess of 75 feet in height. Ha ha.

Even with sprinklers, if the A-3 has occupancy in excess of 300, a fire alarm system (907.2.1) with notification is required. No pull boxes required due to the sprinklers. Typically for an A-3 without fixed furniture, occupancy must be listed on the documents for all three conditions: tables and chairs, chairs only, and standing. Don't let them declare 299 occupants because that's what the owner says; floor area's square feet trumps the owner's claims. I am familar with the exception to 1004.1.1; that's supposed to be applied to aircraft hangers and indoor tennis facilities, not to worm out of providing a life safety system.

I agree that accessible access is not required to a floor of under 3,000 square feet, no matter what. I raised this issue on another thread months ago and finally received a good answer: the specific always trumps the general (102.1). Generally, all levels are required to be connected by an accessible route, unless they are specifically under 3,000 square feet.

 

[Examiner]

Thank you all. The building does not have a floor above 75-feet. The floor's total occupant load exceeds 300. Which brings up questions. The Table allows 50-sf per person for locker rooms, weight rooms and exercise rooms. However, the number of lockers and possible people using the locker room will be over the calculated loading. EX: a varsity locker room will dress out at one time more people than the calculated occupant load that is based on the floor area. There are three locker rooms, Varsity, Junior Varsity both used for football and basketball. There is a third locker room titled "Softball / Cheerleaders". I assume that that room is for Cheerleaders in the football and basketball season and for softball players in the softball season for girls.

The Code requires worst case scenario of all rooms being occupied at one time and this makes the occupant load over 300. The probability of all rooms being occupied to the fullest at one time is remote. Why does not the Code take this into account? or Should I just count the calculated occupant load based on floor area which will bring down the occupant load to under 300? What to do?????

 

[texasbo]

I would use the table and assume all spaces occupied simultaneously.

 

[vegas paul]

Agree with texasbo. The reason that the code doesn't "take into account" that it is remote that all areas be simultaneously occupied, is because history has shown that it isn't all that remote! And bad things usually happen during the "remote" circumstances, anyway. Build it to the code, and then you don't have to explain to any grieving students/parents why you thought that less than code was good enough for them...

 

[brudgers]

The Code requires worst case scenario of all rooms being occupied at one time and this makes the occupant load over 300. The probability of all rooms being occupied to the fullest at one time is remote. Why does not the Code take this into account? or Should I just count the calculated occupant load based on floor area which will bring down the occupant load to under 300? What to do?????

Occupant load for the building code is determined by the building code. If the code is 1 per 50, then that's what is required. .

 

[peach]

What are they storing that qualifies as S-1? Start as non separated uses.. if it works, it's easiest. 2 story structure? why would you even consider looking at high rise provisions?

 

[Examiner]

Well S-1 is for items that will burn. Since it is a field house; I am sure there will be combustible items in the Storage areas. Football pads/dummies, clothing and boxes to keep some of the items in.

The High Rise question was asked because Section 508.3.2.1 stated to follow that section and Chapter 9.

508.3.2.1 Occupancy classification. Nonseparated occupancies shall be individually classified in accordance with Section 302.1. Code requirements shall apply to each portion of the building based on the occupancy classification of that space except that the most restrictive applicable provisions of Section 403 and Chapter 9 shall apply to the entire building or portion

thereof.

 

[texasbo]

Agree with High Desert that the reference to 403 is just a pointer for the cases where it comes into play.

 

[mtlogcabin]

However, the number of lockers and possible people using the locker room will be over the calculated loading. EX: a varsity locker room will dress out at one time more people than the calculated occupant load that is based on the floor area.

The code allows you to use an increased occupant load provided the means of egress design includes the increased OL

0226 IBC 1004.2 Increased occupant load.

The occupant load permitted in any building, or portion thereof, is permitted to be increased from that number established for the occupancies in Table 1004.1.1, provided that all other requirements of the code are also met based on such modified number and the occupant load does not exceed one occupant per 7 square feet (0.65 m2) of occupiable floor space.