Restroom Occupancy classification

[lynn2000]

what occupancy classification do restrooms on airport concourse level belong to? Most of the spaces on this level are A-3. Should these restroom be categorized as A-3, I see some people put them to B.

 

[RLGA]

Although restrooms are where people go "to do their business," I would not classify them as a Group B occupancy if they are there to support a Group A-3 occupancy--I would classify them as part of the Group A-3 occupancy.

I typically classify the restrooms as part of the occupancy they are located in and primarily support. If the restrooms are part of an office area, I would classify them as part of the Group B occupancy. If the restrooms are located within a Group A occupancy but are also used by the Group B occupancy, I would still classify them as part of the Group A occupancy.

 

[lynn2000]

Although restrooms are where people go "to do their business," I would not classify them as a Group B occupancy if they are there to support a Group A-3 occupancy--I would classify them as part of the Group A-3 occupancy.

I typically classify the restrooms as part of the occupancy they are located in and primarily support. If the restrooms are part of an office area, I would classify them as part of the Group B occupancy. If the restrooms are located within a Group A occupancy but are also used by the Group B occupancy, I would still classify them as part of the Group A occupancy.

Yeah, I agree. Your comments make sense - since the restrooms are there supporting the main occupancy.

 

[Yikes]

Although restrooms are where people go "to do their business," I would not classify them as a Group B occupancy if they are there to support a Group A-3 occupancy--I would classify them as part of the Group A-3 occupancy.

I typically classify the restrooms as part of the occupancy they are located in and primarily support. If the restrooms are part of an office area, I would classify them as part of the Group B occupancy. If the restrooms are located within a Group A occupancy but are also used by the Group B occupancy, I would still classify them as part of the Group A occupancy.

Do you count the occupant load of the restrooms as part of the cumulative occupant load? Or do you assume that the people using the restrooms were already counted in the other spaces that the restrooms serve?

 

[Tim Mailloux]

Do you count the occupant load of the restrooms as part of the cumulative occupant load? Or do you assume that the people using the restrooms were already counted in the other spaces that the restrooms serve?

if the restrooms are part of the A3 occupancy they would not be included in the Net floor area for the occupant load calculation and would not have any OL. If they were part of a Business occupancy then they would be included in the Gross Floor area for the occupant load calculations and the area of the toilets would add to the OL.

 

[steveray]

if the restrooms are part of the A3 occupancy they would not be included in the Net floor area for the occupant load calculation and would not have any OL. If they were part of a Business occupancy then they would be included in the Gross Floor area for the occupant load calculations and the area of the toilets would add to the OL.

Correct, but they would be part of the A3 fire area and mixed uses is not a concern....Depending on where the OP was driving...

 

[lynn2000]

Do you count the occupant load of the restrooms as part of the cumulative occupant load? Or do you assume that the people using the restrooms were already counted in the other spaces that the restrooms serve?

Theoretically, I think occupants that use the restrooms are already counted in the other spaces; but for the project I am working on, we decided to overdesign so we counted the occupant loads of the restrooms as well.

 

[blugosi]

Regardless of occupancy classification, the Airport Terminal OLFs are defined in table 1004.5 based on the classification to concourse / baggage reclaim / baggage handling and waiting areas (boarding queues, security screening etc.)
All these OLFs are gross, they match the relevant OLFs of NFPA 101 and NFPA 415 "Standard on Airport Terminal Buildings, Fueling Ramp Drainage, and Loading Walkways"
Why are you looking at the general OLFs for the A-3?
Retail shops in terminal buildings are a debatable case when the NFPA OLFs are applied, that's why I recommend using IBC OLFs in those areas.

 

[lynn2000]

if the restrooms are part of the A3 occupancy they would not be included in the Net floor area for the occupant load calculation and would not have any OL. If they were part of a Business occupancy then they would be included in the Gross Floor area for the occupant load calculations and the area of the toilets would add to the OL.

Are there any codes that require the restrooms to participate OL calculations for Occupancy B? For example, we have a level planned as office area, people who use the restrooms are actually the people who use the office as well, won’t taking restrooms into OL considerations double the OLcount?

 

[steveray]

Are there any codes that require the restrooms to participate OL calculations for Occupancy B? For example, we have a level planned as office area, people who use the restrooms are actually the people who use the office as well, won’t taking restrooms into OL considerations double the OLcount?

B is calculated as gross so everything is included....

[BE]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, ramps, 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.

 

[Tim Mailloux]

B is calculated as gross so everything is included....

[BE]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, ramps, 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.

View attachment 15190

Everything goes into the gross area including toilets, corridors, mechanical shafts, elevator shafts and stair shafts...basically anything with a roof or floor overhead gets included.

 

[Yikes]

Toilets stalls = "GROSS" floor area

How true.

 

[Yankee Chronicler]

Restrooms are not classified as any occupancy. Restrooms are considered as "not normally occupied" spaces. In an occupancy where the occupant load is calculated on a gross floor area basis, the restrooms are included in the gross floor area because they are not among the items the code tells us to exclude. For occupancies with the occupant load calculated on a net square foot basis, restrooms are not counted toward occupancy and have no occupancy assigned to them.

 

[lynn2000]

Now I have new question.

I started to get the gross floor area for this Business Level and was going to use 150 as Load Factor; Then realized on this level there are many MEP rooms which serve the whole building including the ground level A-3, so should I exclude them from B and use S-2 to do the calculations? Of course if do not take them out of B, we will design for more occupants, it is safer.

 

[steveray]

Now I have new question.

I started to get the gross floor area for this Business Level and was going to use 150 as Load Factor; Then realized on this level there are many MEP rooms which serve the whole building including the ground level A-3, so should I exclude them from B and use S-2 to do the calculations?

Typically see those as storage 300 gross

 

[Joe.B]

Restrooms are not classified as any occupancy.

Our bathroom here should be an H-4...

It can be highly toxic at times.

 

[Sifu]

Now I have new question.

I started to get the gross floor area for this Business Level and was going to use 150 as Load Factor; Then realized on this level there are many MEP rooms which serve the whole building including the ground level A-3, so should I exclude them from B and use S-2 to do the calculations? Of course if do not take them out of B, we will design for more occupants, it is safer.

Don't get caught up conflating classification with occupant load. T1004.5 calculates based on the use, not the classification of the space.