# Open office space with workstations - occ load



## Linda (May 9, 2013)

I am doing a tenant improvement exiting calculation for an office building.  3 story building, 2 stairs, 21,000 sf./floor, Type I-B construction, sprinklered, California Building Code.  Most of the office space is open, with workstations and a few private offices and a few conference rooms. The intent is to not create any corridors on the 2nd & 3rd floors.  Tenant wants the space to feel very open.  Most office and conf. room walls are glass.  Stairs and elevator shafts are 2-hour rated.  Stairs will feed into rated corridors on the ground floor.

My question is:  how is the occupant load figured when the space is "open" for workstations to be installed?  There will have to be "clear paths" between workstations for circulation and accessibility.  Do we have to count the potential "clear paths" at 100 sf/occupant, or can we deduct that area from the floor area before calc'g the open spaces at 100 sf/occ?  Conf rooms will be calc'd at 15 sf/occ.

Thanks


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## mark handler (May 9, 2013)

Business areas 100 sf *GROSS*

Gross floor area includes the aisles between the “cubicles”

("net would not include the aisles between the “cubicles” ) Code requires GROSS

 If the corridor is defined with walls as a separate space it does not count as habitable space

Conference rooms can sometimes be counted as business space rather than “assembly” space but cannot tell based on what you posted

Exception 3 to 2010 CBC Section 303.1. A space less than 750sf used for assembly purposes is Group B, or part of the occupancy to which it is accessory.

FLOOR AREA, GROSS. The floor area within the inside perimeter

of the exterior walls of the building under consideration,

exclusive of vent shafts and courts, without deduction for corridors,

stairways, closets, the thickness of interior walls, columns

or other features. The floor area of a building, or portion thereof, not provided with surrounding exterior walls shall be

the usable area under the horizontal projection of the roof or

floor above. The gross floor area shall not include shafts with

no openings or interior courts.

FLOOR AREA, NET. The actual occupied area not including

unoccupied accessory areas such as corridors, stairways, toilet

rooms, mechanical rooms and closets.


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## cda (May 10, 2013)

agree 100 no different then a bunch of desks

as  far as circulation, code does not seem to address spacing of desks/cubicles. Cannot speak to accessibility requirements.

A corridor situation  will not be created by the cubicles.


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## mtlogcabin (May 10, 2013)

I have counted the number of work stations you can usually find it on the electrical sheets if they do not have a furniture layout and had an occupant load  greater than the 100 gross the code uses.  Can make a difference for plumbing fixtures and maybe exit width with the size building you are dealing with.


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## mark handler (May 10, 2013)

mtlogcabin said:
			
		

> I have counted the number of work stations you can usually find it on the electrical sheets if they do not have a furniture layout and had an occupant load  greater than the 100 gross the code uses.  Can make a difference for plumbing fixtures and maybe exit width with the size building you are dealing with.


You might be able to mitigate the extra load by increasing the life safety, add exits, add sprinklers.....


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## Builder Bob (May 10, 2013)

The only issue of cubicles is usually the common path of travel........


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## fatboy (May 10, 2013)

Cut to the chase.........100 gross.

JMHO.......


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## cda (May 10, 2013)

Linda said:
			
		

> I am doing a tenant improvement exiting calculation for an office building.  3 story building, 2 stairs, 21,000 sf./floor, Type I-B construction, sprinklered, California Building Code.  Most of the office space is open, with workstations and a few private offices and a few conference rooms. The intent is to not create any corridors on the 2nd & 3rd floors.  Tenant wants the space to feel very open.  Most office and conf. room walls are glass.  Stairs and elevator shafts are 2-hour rated.  Stairs will feed into rated corridors on the ground floor.My question is:  how is the occupant load figured when the space is "open" for workstations to be installed?  There will have to be "clear paths" between workstations for circulation and accessibility.  Do we have to count the potential "clear paths" at 100 sf/occupant, or can we deduct that area from the floor area before calc'g the open spaces at 100 sf/occ?  Conf rooms will be calc'd at 15 sf/occ.
> 
> Thanks


Something like this;;;

http://teriflynn.files.wordpress.com/2010/02/full-office-cubicles-449-297.jpg

Or;

http://www.matternetwork.com/images/Matter/office_cubicles_325.jpg

Or;

http://www.sandiegocubicles.com/blog/wp-content/uploads/2011/05/FirstOffice_Staks_1-image1-1304969579_tn.jpg

http://workspacesolutions.com/blog/wp-content/uploads/2011/12/Decline-of-the-Cubicle.jpg

My favorite ;;; cannot say where it is at

http://www.b2binsights.com/wp-content/uploads/2012/11/cubicle-vs-open.jpg


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## RLGA (May 10, 2013)

Like the others have mentioned, use 100 sq. ft. gross; and listen to Builder Bob about the common path of egress travel.

However, I have a question about the following in your statement:



			
				Linda said:
			
		

> Stairs will feed into rated corridors on the ground floor.


CBC Section 1022.2 requires that exit enclosures terminate at an exit discharge or a public way.  In other words, they must exit directly to the exterior and not a corridor; however, an exit passageway is permitted per the exception to that section and must comply with Section 1022.2.1.  if the exit enclosures do not exit directly to the exterior, then make sure that the "corridors" are deigned as exit passageways.


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## Linda (May 10, 2013)

Exception 3 to 303.1 -- we were debating this in our office.  So, any conference room that is less than 750 sq. ft. can be calc'd at 100 sf gross?  I have never tried to use that Exception before, but will definitely go for it if you folks give this interpretation.  Thanks to all for your responses -- great help as always!  The photos of cubicles were scarey -- our client has a much more "luxurious" spacing of workstations  

TGIF,

Linda AIA


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## RLGA (May 10, 2013)

The exception means that assembly spaces less than 750 sq. ft. can be classified as Group B.  However, the occupant load of the space is still based on the appropriate assembly factor in Table 1004.1.1.

The occupant load of the floor may be calculated at the 100 sq. ft., assuming that the users of the conference room are the employees occupying cubicle spaces on the floor and if permitted by the building official.  However, I have seen the occupant load of the floor based on the sum of the office area occupant load calculated at 100 sq. ft. per occupant and the conference room occupant load calculated at the appropriate factor.


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## fatboy (May 10, 2013)

Agree with RGLA......


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## Linda (May 10, 2013)

Rats -- guess it will depend on how the Bldg Official interprets the conference rooms.  It will definitely be the same people using the conf. rooms as the workstations.

Thanks for all the input!

Linda AIA


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## mark handler (May 10, 2013)

Linda

Many BO accept the idea that the conference rooms are used by the office occupants. Not per code but if the OL numbers don't work for you, you could try it. Or Not per code, call it a private office....


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