Appeal 34928

OSSC Section 903.2.1.3: Automatic Sprinkler Systems – Group A-3

OSSC Chapter 34 Requirements: Section 3405.6.1.1 Change in the character of use. Changes within the same occupancy classification that subject the structure to any special provisions of this code require building official approval. Compliance shall be only as necessary to meet the specific provisions and is not intended to require the entire building be brought into compliance.

The removal of fixed seating in the sanctuary will result in a new occupancy condition and require compliance with current code provisions for the recalculated occupant load.

OSSC Chapter 9 Requirements: The revised overall building occupant load – with the inclusion of a recalculated load in the sanctuary – exceeds the maximum allowed occupancy for an unsprinkled building containing Group A-3 occupancies under current code.

Section 903.2.1.3 requires automatic sprinklers throughout stories containing Group A-3 occupancies where the fire area exceeds 12,000 SF, has an occupant load of 300 or more, or is located at a level other than a level of exit discharge.

The intent of the appeal is to limit the installation of automatic fire sprinklers to an area of the building that contains the proposed alteration and associated A-3 classified work area, and is separated from other building areas with a proposed 2-hour fire barrier.

In lieu of installing fire sprinklers throughout the stories containing A-3 occupancies, we propose separating the building into two fire areas: one containing the sanctuary area and basement (Assembly wing) and a second fire area containing smaller classrooms and offices (Business wing). The proposed design includes installation of an approved automatic sprinkler system in the Assembly wing only. No work is proposed in the business wing.

The proposed separation will meet the requirements for a two-hour fire barrier with 90-minute fire protection at openings.

Adding automatic sprinklers to the primary areas of assembly complies with the intent of both the prescriptive and work area methods per Chapter 34 and improves life safety conditions for building occupants. The proposed change in the character of use of the space does not increase the occupant load as previously permitted.

The limited nature of the proposed building alteration – the removal of fixed seating – when considered independently as a level 2 building alteration as defined by 3406.3.1, does not trigger sprinklers per Section 3408.3.2.2 , as the area of work does not exceed 50% of the floor area.

The two separated fire areas each independently comply with Section 903.2.1.3 and the proposed separation will comply with Section 707 for fire barriers.