R-2 Rooftop Pation and Number of Stories

2010 CBC applies.

I'm looking at a 4-story, R-2 condominium building. The architect has provided a rather large rooftop patio that could easily handle up to 500 occupants using a 7 sf/occ. factor for assembly use.

My concern is this, since the architect has identified this as a Type VA building, sprinklered throughout with a NFPA 13 system, the allowable height and area, including increases for both, complies with Chapter 5. However, the rooftop patio can easily be classified as a Group A-3. Table 503 limits Group A-3 to 2 stories (3 stories with sprinkler increase), but since this rooftop patio is technically not a story by definition (no roof above), then is this acceptable?

I know means of egress need to comply with Chapter 10 per Section 1004.8.

Ron Geren RLGA Technical Services Phoenix AZ
Original Post
Even if you were able to limit the occupant load such that it a B o0ccupancy, it is still not allowed above the third story. Same as if you called it an R-2.

I believe that Mark is correct in that the type of construction will have to change.

Chuck Daleo
There are some questions that come to mind;
What is the total occupant load for the building plus guests for each suite?
Could you fit the total occupant load on the roof at one time?
Was the roof designed to hold the total occupant load, plus occupant’s guests?
Is there room for three exits to the public way ?
What is the total s.f. of the building?
What is the total s.f of the rooftop? 3500s.f. using 500 x7?
Are the zoning people allowing the patio on the roof?
Why is the occupant factor of 7ft used, this is not a rooftop honky tonk saloon?
This a residential building.
Sprinklers allow another story +20ft.
Residential Occupancy Factor 200 gross = 18 occupant load
The structure “Patio” is a U.
Will the structure “patio” require it to be sprinklered, Yes.
Can you mandate it be built out of the same materials as the building was, Yes.
Will the sides have the correct guards? Yes.

If they leave the patio off and they have the parties anyway who is going to regulate the use?
Why not just build a mezzanine?

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