Net Area in Unconcentrated Space

[Phil B]

I have seen both yes and no answers to this question, but would like current thoughts or opinions. Apologies if this has been answered elsewhere in this forum but I couldn't find it.

The light purple area In the sketch below would be where the 15 sf / person would apply. The light brown areas are fixed booth seating. The question is could the areas hatched in orange be deducted from the net area for the tables and chairs since this area would need to be always open for exiting from the booths and thus could not contain any tables and chairs, or does the 15 sf/person factor take this into account?

 

[RLGA]

My response would be no, you cannot deduct that area. The occupant load factors take into consideration required circulation for aisles. The only time I would deduct a portion of an assembly area from the occupant load is if the area is clearly defined as circulation and cannot be easily used for assembly purposes (e.g., railings, divider walls, etc.).

 

[Yankee Chronicler]

Based in the IBC definitions, I think you can deduct those areas, and use the methods of calculating occupant load provided in the IBC for areas with fixed seating.



But, keep in mind that it's a restaurant. For overall design purposes, I would suggest a cross-check using the entire dining room area at 15 sf/person as a check. In the past couple of years I've reviewed several restaurant alterations where they removed booths and installed tables and chairs instead. You don't want to lock the owner into an overall building plan that might require later adding exit doors if they change from booths to tables. I'm not so sure you can also deduct the access aisles the way you have shown. At the moment, I think the fixed seating applies only to the area occupied by the booths.

 

[Phil B]

Based in the IBC definitions, I think you can deduct those areas, and use the methods of calculating occupant load provided in the IBC for areas with fixed seating.

View attachment 16055

But, keep in mind that it's a restaurant. For overall design purposes, I would suggest a cross-check using the entire dining room area at 15 sf/person as a check. In the past couple of years I've reviewed several restaurant alterations where they removed booths and installed tables and chairs instead. You don't want to lock the owner into an overall building plan that might require later adding exit doors if they change from booths to tables. I'm not so sure you can also deduct the access aisles the way you have shown. At the moment, I think the fixed seating applies only to the area occupied by the booths.

Agree! The fixed booths on the left side are staying no matter what. I added them on the right side to see if the occupancy drops to below 49 if the 'access' areas could be deducted....nope! Excellent point on the future what if. Thank you both for your input!

 

[bill1952]

My response would be no, you cannot deduct that area. The occupant load factors take into consideration required circulation for aisles. The only time I would deduct a portion of an assembly area from the occupant load is if the area is clearly defined as circulation and cannot be easily used for assembly purposes (e.g., railings, divider walls, etc.).

Agree. The OLF takes into a count aisles and aisle access ways. In a banquet space with 8 or 10 tops you can get to 1 person in 10 sq ft or less, including all aisle access ways and aisles.

 

[Tim Mailloux]

I am in the no camp as well.