The Code

Occupancy Types

A-2 - Assembly- Restaurant

R-3 - Residential-

        R-3 definition:
"Residential occupancies where the occupants are primarily permanent in nature and not classified as Group R-1, R-2, R-4 or I, including:
Boarding houses (nontransient) with 16 or fewer occupants
Boarding houses (transient) with 10 or fewer occupant"
        Walls separating dwelling units in the same building, walls separating sleeping units in the same building and walls separating dwelling or sleeping units from other occupancies contiguous to them in the same building shall be constructed as fire partitions in accordance with Section 708.
        Group R occupancies shall be equipped throughout with an automatic sprinkler system in accordance with Section 903.2.8.
        Fire alarm systems and smoke alarms shall be provided in Group I-1, R-1 and R-2 occupancies in accordance with Sections 907.2.6, 907.2.8 and 907.2.9, respectively. Single-or multiple-station smoke alarms shall be in accordance with Section 907.2.11.


S-2 - Storage
        S-2 definition:
"Includes, among others, buildings used for the storage of noncombustible materials including: Parking garages, open or enclosed"
         Open parking garages shall be of Type I, II or IV construction        
         For natural ventilation purposes, the exterior side of the structure shall have uniformly distributed openings on two or more sides. The area of such openings in exterior walls on a tier shall be not less than 20 percent of the total perimeter wall area of each tier. The aggregate length of the openings considered to be providing natural ventilation shall be not less than 40 percent of the perimeter of the tier. Interior walls shall be not less than 20 percent open with uniformly distributed openings.
          Closed parking garages:
          A mechanical ventilation system shall be provided in accordance with the International Mechanical Code.
          An enclosed parking garage shall be equipped with an automatic sprinkler system in accordance with Section 903.2.10.

Limits

A-2 - 

        Type I A- 3 hour fire rating

             Unlimited building height, unlimited stories, unlimited floor area

        Type II A- 1 hour fire rating

              65 feet height, 3 stories, 15,500 sf/floor

R3-

        Type I A-

              Unlimited building height, unlimited stories, unlimited floor area

        Type II A-

                65 feet height, 4 stories, unlimited sf/floor

 Mixed Use

"Each portion of a building shall be individually classified in accordance with Section 302.1."

Parking under group R:

         "Where a maximum one story above grade plane Group S-2 parking garage, enclosed or open, or combination thereof, of Type I construction or open of Type IV construction, with grade entrance, is provided under a building of Group R, the number of stories to be used in determining the minimum type of construction shall be measured from the floor above such a parking area. The floor assembly between the parking garage and the Group R above shall comply with the type of construction required for the parking garage and shall also provide a fire-resistance rating not less than the mixed occupancy separation required in Section 508.4."

1 hour separation between A and R with sprinklers.  2 hours without.

No separation between A and S-2 with sprinklers.  1 hour without.

1 hour separation between R and S-2 with sprinklers.  2 hours without.

Miscellaneous

Laundry rooms over 100 square feet require 1 hour separation or automatic sprinkler system.