Net Area in a Lobby Space - Fixed Millwork Included?

[MKALLAY]

I am looking at a project (Museum) that has an entrance lobby space which may also be used for small gatherings - receptions, etc. The space contains several fixed millwork items - reception desk, display cases - which are built in and permanent. In calculating the occupant load for the space, must the floor space occupied by such items be included in the "net floor area" of the space, or can that area be excluded from the net floor area?

 

[arwat23]

No, fixed elements that do not allow people to occupy a space, like millwork, are excluded form "net" load factors.

 

[bill1952]

Do you think if they remove that millwork, they'll get a permit and recalculate occepant load and egress?

 

[ICE]

Do you think if they remove that millwork, they'll get a permit and recalculate occepant load and egress?

Not likely. Might even put in a vending machine without asking for permission.

 

[bill1952]

I just see very little downside to using the room dimensions. If you're within a couple of people if needing another door or means of egress, not sure I want to not add 1. My view as a designer. I realize some would design to eliminate one occupant to save a toilet or a door. I believe the owner would be better off with that toilet or door over the life of the building with changes.

 

[arwat23]

I just see very little downside to using the room dimensions.

More safety is rarely a bad thing, but a 15 net (at best) load factor adds a lot of occupants really quickly. I've experienced many downsides to just using the room area without reduction for fixed elements.

I'm currently working on a project where the reception desk, if it was included in the net area of the waiting room its in, would add 4 occupants by itself. Those 4 occupants are the difference between requiring one exit (existing suite, only has one exit) and two exits (which would be impossible / ungodly expensive to provide).

Another example I've run into more than a few times: In CA, let's say you have an OL of 200 in an office building. 6 water closets (2 men, 4 women) are required. If you hit 201 occupants, you suddenly need 11 water closets (3 men, 8 women) minimum. It's not a matter of a few occupants adding one or two fixtures. A few occupants can change an entire floor plan depending on the project (and jurisdiction).

Why not utilize what code allows? Is it ideal? No, but the wizards that write this stuff say it meets minimum life-safety requirements.

 

[bill1952]

More safety is rarely a bad thing, but a 15 net (at best) load factor adds a lot of occupants really quickly. I've experienced many downsides to just using the room area without reduction for fixed elements.

I'm currently working on a project where the reception desk, if it was included in the net area of the waiting room its in, would add 4 occupants by itself. Those 4 occupants are the difference between requiring one exit (existing suite, only has one exit) and two exits (which would be impossible / ungodly expensive to provide).

Another example I've run into more than a few times: In CA, let's say you have an OL of 200 in an office building. 6 water closets (2 men, 4 women) are required. If you hit 201 occupants, you suddenly need 11 water closets (3 men, 8 women) minimum. It's not a matter of a few occupants adding one or two fixtures. A few occupants can change an entire floor plan depending on the project (and jurisdiction).

Why not utilize what code allows? Is it ideal? No, but the wizards that write this stuff say it meets minimum life-safety requirements.

Fair points. I primarily deal with performing arts theatres with an average of 700-800 seats. Never enough toilets at intermission. Lobbies are never big enough for the number of seats so always crowded. I do use the 50 person 1 moe at times for some seating areas and support rooms. I find cultural institutions - like museums and theatres - are always changing - looking for income - which usually means more people and activities not envisioned.

 

[Yankee Chronicler]

More safety is rarely a bad thing, but a 15 net (at best) load factor adds a lot of occupants really quickly. I've experienced many downsides to just using the room area without reduction for fixed elements.

An entrance lobby is hardly likely to be used with tables and chairs, or even chairs-only lecture seating. I would view an entrance lobby as calling for the occupant load to be calculated at 1:5, for standing occupants.

Fixed millwork is deducted when using net square foot occupancy factors.

 

[bill1952]

An entrance lobby is hardly likely to be used with tables and chairs,

"entrance lobby" is a slightly vague term. I don't know what distinguishes a "lobby" from an "entrances lobby". I'm planning theatres, I assume the lobby is an assembly space and used for many things, especially those that represent income. Several projects in Detroit - just assumed you can get a car into the lobby. I've done layouts for 8 and 10 too tables for lobbies. Several projects the lobby has more net sq ft than the auditorium. The OP mentioned receptions. Redesigned one theatre in a pac so it could be used simultaneously with lobby when it was rented for weddings. Income. I've designed lighting for lobby performances.

I'd certainly use 5 sf as the OLF. The harder part is if using net, should a wide corridor be included, since I know it will be occupied just like the lobby.

 

[Tim Mailloux]

net calculations can deduct built in fixed casework as you described, gross calculations must include them.

 

[MKALLAY]

I find cultural institutions - like museums and theatres - are always changing - looking for income - which usually means more people and activities not envisioned.

This was my point to the designer - they were trying to keep the occupant load low enough to avoid two exits from the space, but in doing so, potentially limiting the use of the space. Better to find a solution to the egress problem, IMO, than to box in the client to limit their use of the space.

Thank you all for your input!

 

[arwat23]

An entrance lobby is hardly likely to be used with tables and chairs, or even chairs-only lecture seating. I would view an entrance lobby as calling for the occupant load to be calculated at 1:5, for standing occupants.

Depends on the lobby. I'm use to business offices and medical office lobbies, which almost always have tables and chairs. But yeah, I can see a museum lobby only having standing space.

 

[Tim Mailloux]

This was my point to the designer - they were trying to keep the occupant load low enough to avoid two exits from the space, but in doing so, potentially limiting the use of the space. Better to find a solution to the egress problem, IMO, than to box in the client to limit their use of the space.

Thank you all for your input!

as one of my mentors use to tell me "....code is the bare minimum standard we have to meet; we can do better than the bare minimum..."

 

[bill1952]

as one of my mentors use to tell me "....code is the bare minimum standard we have to meet; we can do better than the bare minimum..."

Or code is a necessary condition but often not sufficient.