Appeal 8489

1014.3

Common path of egress travel. In occupancies other than Groups H-1, H-2 and H-3, the common path of egress travel shall not exceed 75 feet. In Groups H-1, H-2 and H-3 occupancies, the common path of egress travel shall not exceed 25 feet. For common path of egress travel in Group A occupancies and assembly occupancies accessory to Group E occupancies having fixed seating, see Section 1028.8.
Exceptions:

1. The length of a common path of egress travel in Group B,F and S occupancies shall not be more than 100 feet, provided that the building is equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.
2. Where a tenant space in Group B, S and U occupancies has an occupant load of not more than 30, the length of common path of egress travel shall not be more than 100 feet.
3. The length of a common path of egress travel in a Group I-3 occupancy shall not be more than100 feet.
4. The length of a common path of egress travel in a Group R-2 occupancy shall not be more than 125 feet, provided that the building is protected throughout with ana approved automatic sprinkler system in accordance with Section 903.3.1.1. or 903.3.1.2.

The design will meet all the requirements of section 1014.3 except that the common path of egress travel exceeds 100 feet. The floor is B occupancy office space. The point of common path of egress travel occurs at an exit enclosure entry door.

We are proposing to allow us to extend the common path of egress travel at this location to approximately 110 feet, 10 feet further than allowed by code for B occupancy. To provide equivalent protection we are proposing to provide a 2 hour rated exit corridor within which the extended common path of egress travel is contained. The common path of egress travel will be within the exit corridor after an egress travel distance of 86 feet. The exit enclosure and elevator hoistway opening into the corridor are pressurized.

The alternate measures are:

1. 2 hour fire-rated exit corridor with fire barrier walls and 90 minute fire-rated doors.
2. Type 1A construction.
3. Quick response sprinkler system.
4. Early warning fire and smoke detection system.
5. Pressurized exit enclosure and elevator hoistway.

The reason for the exit corridor in this location is to provide a rated enclosure where 2 separate single exit office spaces meet. The exit corridor extends the common path of egress travel from these offices to the exit enclosure or to the corridor which leads to the second exit enclosure. The exit corridor provides additional protection for the occupants to exit. This condition only exists in this one location in the building and is caused by the special configuration of the offices in this area. Security of the entrances to the offices has mandated the size and configuration.

The intent of the common path of egress travel limit is to provide occupants access to two means of egress within a safe time frame. Quick response sprinkler system allows the corridors to be non-rated. By providing a 2 hour rated exit corridor, we are providing additional protection for occupants to travel the common path. Based on movement data from the SFPE Handbook, travel time for the additional 10 feet is 3 seconds. The design provides this extended travel distance to occur in a 2 hour rated protected corridor. The building is B occupancy of Type 1A construction, sprinklered throughout with early warning smoke a d fire detection systems and pressurized exit and elevator hoistway enclosures.

Therefore we feel the 2 hour rated exit corridor provides equivalent protection for the common path of egress travel to exits and request approval of this request.

708.2, exception 11

Shaft enclosure required. Openings through a floor/ceiling assembly shall be protected by a shaft enclosure complying with this section.

Exceptions:

1. A shaft enclosure is not required for openings totally within an individual residential dwelling unit and connecting four stories or less.
2. A shaft enclosure is not required in a building equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 for an escalator opening or stairway that is not a portion of the means of egress protected according to Item 2.1 or 2.2.

2.1. Where the area of the floor opening between stories does not exceed twice the horizontal projected area of the escalator or stairway and the opening is protected by a draft curtain and closely spaced sprinklers in accordance with NFPA 13. In other than Groups B and M, this application is limited to openings that do not connect more than four stories.
2.2. Where the opening is protected by approved power-operated automatic shutters at every penetrated floor. The shutters shall be of noncombustible construction and have a fire-resistance rating of not less than 1.5 hours. The shutter shall be so constructed as to close immediately upon the actuation of a smoke detector installed in accordance with Section 907.3 and shall completely shut off the well opening. Escalators shall cease operation when the shutter begins to close. The shutter shall operate at a speed of not more than 30 feet per minute (152.4 mm/s) and shall be equipped with a sensitive leading edge to arrest its progress where in contact with any obstacle, and to continue its progress on release therefrom.

1. A shaft enclosure is not required for penetrations by pipe, tube, conduit, wire, cable and vents protected in accordance with Section 713.4.
2. A shaft enclosure is not required for penetrations by ducts protected in accordance with Section 716.6. Grease ducts shall be protected in accordance with the International Mechanical Code.
3. In other than Group H occupancies, a shaft enclosure is not required for floor openings complying with the provisions for atriums in Section 404.
4. A shaft enclosure is not required for approved masonry chimneys where annular space is fireblocked at each floor level in accordance with Section 717.2.5.
5. In other than Groups I-2 and I-3, a shaft enclosure is not required for a floor opening or an air transfer opening that complies with the following:

7.1. Does not connect more than two stories.
7.2. Is not part of the required means of egress system.
7.3. Is not concealed within the construction of a wall or a floor/ceiling assembly.
7.4. Is not open to a corridor in Group I and R occupancies.
7.5. Is not open to a corridor on nonsprinklered floors in any occupancy.
7.6. Is separated from floor openings and air transfer openings serving other floors by construction conforming to required shaft enclosures.
7.7. Is limited to the same smoke compartment.

1. A shaft enclosure is not required for automobile ramps in open and enclosed parking garages constructed in accordance with Sections 406.3 and 406.4, respectively.
2. A shaft enclosure is not required for floor openings between a mezzanine and the floor below.
3. A shaft enclosure is not required for joints protected by a fire-resistant joint system in accordance with Section 714.
4. A shaft enclosure shall not be required for floor openings created by unenclosed stairs or ramps in accordance with Exception 3 or 4 in Section 1016.1.
5. Floor openings protected by floor fire doors in accordance with Section 712.8.
6. In Group I-3 occupancies, a shaft enclosure is not required for floor openings in accordance with Section 408.5.
7. A shaft enclosure is not required for elevator hoistways in open or enclosed parking garages that serve only the parking garage.
8. In open or enclosed parking garages a shaft enclosure is not required to enclose mechanical exhaust or supply duct systems when such duct system is contained within and serves only the parking garage.
9. Where permitted by other sections of this code.

Stair 1SS is a one-story stair between two adjacent stories, Level 1 and Park 1. It is a communicating stair providing access from the bike storage area to the lobby. It is not a required means of egress. It complies with all the requirements of section 1016.1 exception 3 which allows unenclosed exit access stairs that connect two adjacent stories. Section 708.2 exception 11 would require that the stair not be an enclosed shaft. This appeal is to allow the stairs to be enclosed.

The design provides a 2-hour fire barrier around the stair to provide protection for building security, occupancy separation and atrium separation. The stair is enclosed with 2 hour fire barrier walls with 90 minute fire-rated doors. The rating of the fire barrier is in compliance with section 708.4 which requires the enclosure to be equal to the floor rating of a Type IA building. There are no electrical, mechanical or plumbing system penetrations into the enclosure. The enclosure of the stair provides additional protection for egressing occupants. The distance to exit discharge from the multi-purpose room it serves is less than required for an unenclosed stair.

The following features of the design assure that an unsafe condition is not created. The occupant load served by this stair is less than 20 people. The distance between the door at the bottom of the stair and the exit discharge door is less than 50 feet. The path to the exit door is direct and easily discernible. There are Illuminated exit signs that mark the exit and the egress path to the exit door will be clearly delineated with stripes on the floor to keep the egress path clear.

The alternate measures proposed are:

1. A 2-hour fire barrier provides opening protection at both levels.
2. The exit access path across the bike storage room floor will be striped.

The stair provides convenient access between the bicycle storage room and the ground level lobby. Due to the connection to the bike storage and building security at the stair needs to be provided. Providing enclosure at the top or bottom of the stair negates the intent of allowing open stairs and necessitates enclosure. Any shaft enclosure must equal the fire rating of the floor it penetrates. Therefore a stair enclosure is required and must be 2 hour rated to provide for building security from the bike storage area. The 2 hour rated enclosure provides better protection than the unenclosed stair allowed by code.

The design includes features that assure an unsafe condition is not created. The exit access from the bottom of the stair to the exit door is direct and discernible. The pathway to the exit will be delineated by floor striping to assure that bicycle storage does not encroach onto the egress pathway. Striping exceeds code requirements and provides better than code safety. Exit signs clearly mark the path and exit discharge and the building is protected by quick-response sprinklers.

Therefore equivalent protection is provided by the stair enclosure and paint stripe exit path marking and request approval of this request.

1018.4

Dead ends. Where more than one exit or exit access doorway is required, the exit access shall be arranged such that there are no dead ends in corridors more than 20 feet in length.

The design exceeds the distance limitation of section 1018.4 for A occupancy. The length of the dead end is 29 feet. The dead end corridor only occurs on level 2 of the building. Level 3 provides access to the learning studio and has a dead end corridor length less than 20 feet.

In order to provide 1/3 separation, we have a 29 foot dead end corridor. The vertical alignment of the space entrance separated by 2 hour construction did not permit the door being closer to the exit door. The two exits from the lecture hall are greater than one third the diagonal within the lecture hall and enter into corridors on separate levels. The corridors each exit enter into are protected with 1 hour rated fire barriers with 45 minute fire-rated doors. The corridor at the southern end of the lecture hall was designed to meet the 1/3 diagonal dimension requirement.

We request approval to allow the dead end corridor to exceed the 20 feet and for the 2 exits from the lecture hall be separated by a two hour floor construction. Several features of the design assure that safety and protection are not compromised.

1. The corridors on both levels are served by the atrium smoke evacuation system.
2. The building is served by an early warning fire and smoke detection system.
3. The building is Type IA construction.
4. The fire protection system includes quick-response sprinkler system.
5. Egress travel distance to exit enclosure is less than 200 feet as allowed per 404.9.

The stadium style seating of the lecture hall allows exits to occur on two different building levels. Once outside of the hall on each level, the distance to the edge of the exit enclosure is 29 feet. Egress paths from other parts of the building and the vertical alignment of the room enclosure limit the location of the doors to the lecture hall. Consequently the corridors have dead ends that exceed the limit for A occupancies.

The two exit access doors from the lecture hall are stacked in plan on separate levels. The two exit doors are separated by Type 1A construction, providing a 2 hour fire-rated separation between them. The two exit access paths lead to two separate exit doors.

The intent of limiting dead end corridor distance is to ensure people do not get trapped in a location where a number of people can stack and prohibit egress within a reasonable amount of time. Occupants from the remainder of the floor would pass the exit enclosure to go down this corridor, limiting the number of occupants proceeding down the corridor. The remainder of the floor that would use this corridor is B occupancy which allows 50 foot dead end corridors. Additional protection of the corridor is provided by the atrium smoke evacuation system.

The intent of the separation of exits from a space is to provide two distinct exit paths to an egress in case smoke or fire is blocking one of the exits. The two hour rated horizontal assembly and atrium smoke evacuation system provides equivalent protection for fire or smoke developing that would block either exit from the lecture hall. Two exits greater than one third diagonal distance apart provide egress from the space as allowed by code. The ramp at the upper level of the lecture hall is separated from the lecture hall by a full height wall. Egress from the lecture hall enters into two separate corridors separated by two hour rated floor assembly construction. The code allows exits from the space to enter into the same corridor with two directions of travel to an exit. The design provides exiting from the lecture hall into two separate corridors separated by 2 hour rated construction and protected with the atrium smoke evacuation system. The corridors have access to two exit enclosures meeting the intent of the separation requirement.

Therefore we feel these measures provide equivalent protection for egress from the lecture hall and occupants on other parts of the floor level and request approval of this request.

1022.3

Openings and penetrations. Exit enclosure opening protectives shall be in accordance with the requirements of Section 715.

Openings in exit enclosures other than unprotected exterior openings shall be limited to those necessary for exit access to the enclosure from normally occupied spaces and for egress from the enclosure.

Elevators shall not open into an exit enclosure.

The design will meet all the requirements of section 1022.3 except that there will be a non-egress opening in the north wall of the southeast stair at the ground level. The opening is a convenience opening and egress will not be allowed. Exit discharges for occupants on both sides of the opening egressing directly to a public way through other doors.

In order to provide equivalent protection, we will provide a 90 minute fire-rated fire shutter activated by the atrium fire/smoke detection system. The 90 minute rating is allowed for fire shutters in 2 hour fire-rated fire barriers. 2 hour rated fire barriers are allowed for exit enclosures serving four or more stories. To ensure smoke does not enter the enclosure through the fire shutter the stair will be pressurized and the door will be closed upon activation of the smoke evacuation system in the lobby/atrium area.

Although normal circulation is enhanced by this opening, it is not part of the emergency egress system. When the fire shutter is closed, the emergency egress system is not affected. Egress from the stair enclosure is via a pair of doors in the east wall that open directly to the exterior. Egress from the lobby/atrium is by doors in the east wall of the lobby.

The alternate measures proposed are:

1. The fire shutter is connected to the atrium fire and smoke detection system.
2. The fire shutter will remain closed during an emergency. Resetting it requires special knowledge.
3. The stair will be pressurized.
4. The lobby/atrium will be protected by a smoke evacuation system.
5. The lobby/atrium will be protected by quick-response fire protection sprinklers.

The function of the opening in the southeast stair is to provide access to the stairs from the atrium during normal activities. The design intention is that people will use the stairs to easily and quickly access upper floors from the lobby. Increased use of the exit enclosure for normal circulation will provide occupants with greater familiarization of the egress system.

The opening is not a required means of egress for the lobby/atrium or the occupants of the stair. The 90 minute fire-rated fire shutter will close upon activation of the atrium fire and smoke detection system. 90 minute fire-rated doors are allowed for 2 hour fire-rated exit enclosures. The stair pressurization and the smoke evacuation system in the lobby/atrium will prevent smoke from entering the exit enclosure through this door. Quick-response sprinklers will help prevent fire in the lobby/atrium from impeding the egress of occupants in the exit enclosure.

Therefore we feel that the atrium fire/smoke detection system activated fire shutter provides equivalent protection in this situation and request approval of this request.

909.8

Exhaust method. When approved by the building official, mechanical smoke control for large enclosed volumes, such as in atriums or malls, shall be permitted to utilize the exhaust method. Smoke control systems using the exhaust method shall be designed in accordance with NFPA 92B.

The design requires smoke control for the atrium space. The space is a large enclosed volume. We are proposing to use the exhaust method to provide smoke control for the atrium. The exhaust method provides the best approach for smoke control in this building.

The atrium space is five stories high and requires a smoke control system. The engineer smoke report utilizes an exhaust method to provide the smoke control requirements of the code.

We are seeking approval for the performance criteria of the smoke report.

OSSC 708.2

708.2 Shaft enclosure required. Openings through a floor/ceiling assembly shall be protected by a shaft enclosure complying with this section.
Exceptions:

1. A shaft enclosure is not required for openings totally within an individual residential dwelling unit and connecting four stories or less.
2. A shaft enclosure is not required in a building equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 for an escalator opening or stairway that is not a portion of the means of egress protected according to Item 2.1 or 2.2.

2.1. Where the area of the floor opening between stories does not exceed twice the horizontal projected area of the escalator or stairway and the opening is protected by a draft curtain and closely spaced sprinklers in accordance with NFPA 13. In other than Groups B and M, this application is limited to openings that do not connect more than four stories.
2.2. Where the opening is protected by approved power-operated automatic shutters at every penetrated floor. The shutters shall be of noncombustible construction and have a fire-resistance rating of not less than 1.5 hours. The shutter shall be so constructed as to close immediately upon the actuation of a smoke detector installed in accordance with Section 907.3 and shall completely shut off the well opening. Escalators shall cease operation when the shutter begins to close. The shutter shall operate at a speed of not more than 30 feet per minute (152.4 mm/s) and shall be equipped with a sensitive leading edge to arrest its progress where in contact with any obstacle, and to continue its progress on release therefrom.

1. A shaft enclosure is not required for penetrations by pipe, tube, conduit, wire, cable and vents protected in accordance with Section 713.4.
2. A shaft enclosure is not required for penetrations by ducts protected in accordance with Section 716.6. Grease ducts shall be protected in accordance with the International Mechanical Code.
3. In other than Group H occupancies, a shaft enclosure is not required for floor openings complying with the provisions for atriums in Section 404.
4. A shaft enclosure is not required for approved masonry chimneys where annular space is fireblocked at each floor level in accordance with Section 717.2.5.
5. In other than Groups I-2 and I-3, a shaft enclosure is not required for a floor opening or an air transfer opening that complies with the following:

7.1. Does not connect more than two stories.
7.2. Is not part of the required means of egress system.
7.3. Is not concealed within the construction of a wall or a floor/ceiling assembly.
7.4. Is not open to a corridor in Group I and R occupancies.
7.5. Is not open to a corridor on nonsprinklered floors in any occupancy.
7.6. Is separated from floor openings and air transfer openings serving other floors by construction conforming to required shaft enclosures.
7.7. Is limited to the same smoke compartment.

1. A shaft enclosure is not required for automobile ramps in open and enclosed parking garages constructed in accordance with Sections 406.3 and 406.4, respectively.
2. A shaft enclosure is not required for floor openings between a mezzanine and the floor below.
3. A shaft enclosure is not required for joints protected by a fire-resistant joint system in accordance with Section 714.
4. A shaft enclosure shall not be required for floor openings created by unenclosed stairs or ramps in accordance with Exception 3 or 4 in Section 1016.1.
5. Floor openings protected by floor fire doors in accordance with Section 712.8.
6. In Group I-3 occupancies, a shaft enclosure is not required for floor openings in accordance with Section 408.5.
7. A shaft enclosure is not required for elevator hoistways in open or enclosed parking garages that serve only the parking garage.
8. In open or enclosed parking garages a shaft enclosure is not required to enclose mechanical exhaust or supply duct systems when such duct system is contained within and serves only the parking garage.
9. Where permitted by other sections of this code.

The atrium contains 3 open stairs that are required means of egress. The atrium space is 4 stories tall and the space around the stairs is more than twice the horizontal length. In all instances the stairs are within the atrium space and exit travel is within 200 feet as required by code. Overall exit travel distance for all spaces using the open atrium stairs comply with table 1016.1.

We are requesting stairs connecting 3 stories in the atrium be allowed to be open. To provide equivalent protection, the design provides a smoke evacuation system. The smoke report includes a timed egress analysis that shows all occupants of the atrium area will have evacuated within the time the smoke evacuation system is required to operate. The longest egress time with safety factors included is 12.6 minutes from any point in the atrium. This is shorter than the 20 minute required operation of the smoke evacuation system. This provides for egress down the open stairs and to an exit discharge without impedance from smoke.

The alternate measures proposed are:

1. Smoke evacuation system.
2. Quick-response sprinkler system.

The stairs provide egress from 3 levels of the atrium space. The stairs from 3 program levels within the atrium space cross through the atrium and down to the exits at the lobby level. Enclosing the stairs is not desirable in the open atrium space. Providing exits from the atrium program spaces through the atrium allows additional means of egress and shorter overall egress travel distances for occupants in the atrium.

The design includes features that assure an unsafe condition is not created. The smoke report with timed egress analysis shows that exiting from all areas of the atrium will occur within 13 minutes. The system is designed to provide 6 feet clear minimum above the highest exit level for the 20 minutes. The egress distance on the open stairs to an exit discharge is less than 200 feet as allowed by code in an atrium. Quick response sprinkler system activated by water flow provides protection for the occupants. The exit access from the bottom of the stair to the exit door is direct and discernible. Exit signs clearly mark the path and exit discharge and the building is protected by quick- response sprinklers.

Therefore equivalent protection is provided by the smoke evacuation system and request approval of this request.