3.1 SCOPE
The provisions of this section shall control the design, construction and arrangement of building components to provide a reasonably safe means of escape therefrom. Buildings shall be evacuated during any repair or alteration works unless the existing means of escape and fire protection system are continuously maintained or other exit and protection measures are taken to provide an equivalent degree of safety.3.2 COMPONENTS OF MEANS OF ESCAPE
3.2.1
A means of escape shall be a continuous and unobstructed way of exit travel from any point in a building to a street, the roof of a building or a designated area of refuge. The path of travel along a means of escape may consist of three parts : (a) the exit access, (b) the exit, and (c) the exit discharge. That portion of the means of escape which leads to the entrance of an exit and is included in the measure of travel distance to reach an exit shall be termed the exit access. The exit itself shall be considered to be that portion of the means of escape which is protected from the area of incidence and provides a safe path to the exit discharge. The exit discharge shall comprise any portion of the travel between the termination of exit and the exterior or the area of refuge.3.2.2
The parts of the means of escape may consist of any of the following exit components : a) A doorway, corridor or passage leading to an exterior or interior staircase, smoke proof and fireproof enclosure, ramp, balcony, fire escape or combination thereof, having direct access to the street, the roof of a building or any designated refuge area which affords safety from fire or smoke from the area of incidence; b) A horizontal exit from the affected building to an adjoining building or an area of refuge at the same level which provides safety from fire and smoke from the area of incidence and the areas communicating therewith.3.2.3
Lifts, escalators and moving walks shall not be regarded as components of means of escape.3.3 GENERAL REQUIREMENTS
3.3.1
All buildings constructed for human occupancy or storage shall be provided with adequate exit facilities to permit safe and quick unaided escape of the occupants in the event of fire or other emergency.3.3.2
An exit shall at no time be used for any purpose that would interfere with its use as a means of escape.3.3.3
Exits and exit access corridors shall not be used as supply or return air ducts.3.3.4
Where changes in elevation not exceeding 300 mm exist in exits or exit access corridors, ramps shall be used. At exterior doors not required to be used by handicapped or aged people, a maximum step down of 200 mm shall be permitted. All exits shall be clearly visible and exit access corridors and passages leading to the exit shall be marked and signposted to guide the occupancy traffic. Exit signs in pubic places used during the hours of darkness and those in areas required to have more than one exit or exit access shall be illuminated in accordance with the provisions of Sec 1.5 of Part 8.3.3.5
The owner or lessee of all new and existing buildings shall be responsible for the safety of all occupants. If in any existing building, the exit facilities are deemed inadequate in view of the requirements of this Code, the Authority may order additional provisions to be incorporated in the building in order to minimize hazard to life of the occupants.3.4 LOCATION AND ARRANGEMENT OF EXITS
3.4.1
All exits shall be easily discernible and accessible from the areas served by them.3.4.2
Exit from any room or space shall not open into an adjoining or intervening room or area except where such adjoining room or area is an accessory to the area served, is not a hazardous occupancy and provide a direct escape to the designated exit area.3.4.3
No portion of an exit route shall pass through a room that may be subject to locking or be intervened by a door that may be locked when the building is occupied.3.4.4
All assembly buildings shall front on at least one street on which the main exit discharge shall be located. The main entrance to an assembly building shall also serve as the main exit capable of providing escape for at least one-half of the total occupant load. For assembly buildings having more than one levels or floors each level shall be provided with additional exits capable of providing escape for at least two-thirds of the occupant load served by that level.3.4.5
All exits shall be so located and arranged that they provide continuous and unobstructed means of escape to the exterior of the building leading to a street or to other designated areas of refuge.3.5 OCCUPANT LOAD
3.5.1 Design Occupant Load
The occupant load for which the exit facilities are to be provided shall be established by the largest number computed by the provisions of (a), (b) and (c) below : a) The actual number of occupants for whom the area served by the exits is designed; b) Number of occupants computed at the rate of one occupant per unit of floor area as prescribed in Table 4.3.1. c) The number of occupants in any area as computed by the provisions of (a) or (b) above plus the number similarly computed for all spaces that discharge through this space in order to gain access to the exit.3.5.2 Fixed Seats
The occupant load for an assembly or educational area having fixed seats shall be determined by the seating capacity of the area. For fixed seats without dividing arms, the capacity shall be taken as one person for every 500 mm of seat.3.5.3 Maximum Occupant Load
The occupant load calculated as above need not exceed one person per 0.3 m² of usable floor space.3.5.4 Mezzanine Floors
The occupant load of a mezzanine floor discharging through a floor below shall be added to the receiving floor’s occupant load.3.5.5 Roofs
Roofs used as assembly, educational or other areas of human occupancy shall be provided with exit facilities for the required occupant load.3.6 CAPACITY OF EXIT COMPONENTS
The capacity of means of exit shall be adequate for the occupant load of the area served thereby. The required width of each exit component shall be computed on the basis of the exit width per occupant prescribed in Table 4.3.2, subject to the minimum width of each such component specified in Sec 3.7, 3.8, 3.9, 3.10, 3.11 and 3.12. Table 4.3.1 Occupant Load for Various Occupancies
Table 4.3.2 Required Exit Width per Occupant
3.7 CORRIDORS AND PASSAGEWAYS
3.7.1
Direct route of access to required exits shall be provided through continuous passageways, corridors or aisles which are maintained free of obstructions. As far as practicable, occupants commencing exit travel at any point along the corridor or passageway shall be lead to an exit irrespective of their direction of travel. The length of a dead end in which no exit door is available shall not exceed 10 m.3.7.2
The minimum required width of corridors and passageways shall be determined on the basis of the occupant load in accordance with the provisions of Sec 3.6, but it shall not be less than the most restrictive of the following : a) 1.1 m where serving an occupant load of more than 50. b) 0.9 m where serving an occupant load of 50 or less. c) 2.4 m in Health Care buildings (Occupancy D) where movement of beds is necessary. d) 1.8 m in Educational buildings (Occupancy B) where the occupant load is more than 150.3.7.3
The width of exit corridors and passageways shall not be less than the aggregate of the required width of doors leading from them towards the exterior.3.7.4
The minimum clear height of the corridors and passageways shall not be less than 2.4 m.3.7.5
All exit access corridors shall have a fire resistance rating of 1 hour or more.3.7.6
Door assemblies opening on to the exit access corridors shall be fire doors having a fire resistance rating of at least 20 minutes when tested in accordance with ASTM E152 without the hose stream test.3.8 ASSEMBLY AISLES
3.8.1
Assembly buildings which contain seats, tables, equipment or displays shall be provided with aisles, free of obstructions, leading to the exit.3.8.2
Exit access aisles may be level or ramped with slopes not exceeding 1 in 8. The clear width of level or ramped aisles shall be obtained at the rate of 5 mm per person, subject to the minimum specified in Sec 3.8.4.3.8.3
When stepped aisles are provided the minimum tread depth shall be 275 mm. The required width per person shall be obtained from the following expressions, subject to the minimum specified in Sec 3.8.5. For aisles with handrails, For aisles without handrails, in which , for rise up to 175 mm, and = the rise, for rise greater than 175 mm. The rise shall not be less than 100 mm nor more than 200 mm.3.8.4
The minimum width of level or ramped aisles shall be as specified below :- Seats on both sides of the aisle: 1 m
- Seats on one side of the aisle: 0.9 m
3.8.5
The minimum width of stepped aisles shall be as specified below :- Seats on both sides of the aisle: 1.2 m
- Seats on one side of the aisle: 1 m
3.8.6
The minimum clear gap between rows, measured as the clear horizontal distance between the back of the row ahead and the nearest projection of the row behind shall be 300 mm. For chairs having automatic or self-rising seats, the measurement shall be made with the seats in the raised position; for non-automatic seats the measurement shall be taken with the seats in the down position.3.8.7
For rows of seats served by aisles or doorways at both ends, the number of seats per row shall not exceed 100. The minimum clear gap between rows shall be increased beyond 300 mm specified in Sec 3.8.6 by 7 mm for each seat in excess of 15, but the clear gap need not exceed 550 mm.3.8.8
For rows of seating served by an aisle or doorway at only one end of the row, the path of travel shall not exceed 10 m from any seat to the aisle or doorway. The minimum clear gap between rows shall be increased beyond 300 mm specified in Sec 3.8.6 by 15 mm for each seat in excess of 7, but the clear gap need not exceed 550 mm.3.9 DOORWAYS
3.9.1
Each occupant of a room or space shall have access to at least one exit or exit access door. The occupant load per exit door and the travel distance up to that door shall not exceed the values specified in Table 4.3.3.3.9.2
Where either the occupant load or the travel distance exceeds the values specified in Table 4.3.3, at least two exit doors shall be provided.3.9.3
The width of a doorway shall not be less than 1 m and the height not less than 2 m.3.9.4
No sliding or hanging door shall be used as a means of exit.3.9.5
All exit access doors shall be of a side-swinging type. When the occupant load exceeds 50, or in a hazardous occupancy, the doors shall swing outward from the room or in the direction of travel. Swinging of the door shall not constrict the width of the corridor below 0.9 m measured at the most critical position.3.9.6
Exit doorways shall not open directly on a flight of stairs. A space of width not less than the width of the doorway shall be maintained immediately outside the doorway. The space shall be at the same level as that of the floor the door serves. Table 4.3.3 Maximum Occupant Load and Travel Distance for Spaces with One Exit Door3.9.7
Revolving doors shall not be used as a means of exit in assembly, educational or institutional buildings or in spaces with an occupant load of 200 or more. In all other cases revolving doors shall not constitute more than half of the total required exit door width. No power operated revolving door that cannot be operated manually in the event of power failure shall be permitted.3.9.8
All exit doors shall be openable from the side they serve without the use of a key.3.10 STAIRWAYS
3.10.1
The required width of exit stairways shall be computed in accordance with the provisions of Sec 3.6, but it shall not be less than the minimum widths specified in Table 4.3.4. Table 4.3.4 Minimum Widths of Exit Stairways3.10.2
The least dimension of landings and platforms in exit stairways shall not be less than the required width of stairway, except that the landing between two stair flights in a straight run shall not be required to be wider than 1.2 m in the direction of travel.3.10.3
The rise and tread dimensions and the headroom requirements shall conform to the provisions Sec 1.12.5 of Part 3.3.10.4
Spiral and winding stairways shall be permitted as an element of a means of escape only within a dwelling unit and from a mezzanine floor not more than 25 m² in area. The minimum width of all such stairways shall be 650 mm with each tread having a minimum depth of 200 mm at a distance of 300 mm from the narrower end. All treads shall be identical. The rise shall not be more than 225 mm with a permissible tolerance of 5 mm between adjacent risers and 10 mm between the largest and the smallest risers.3.10.5
Stairways serving as means of escape shall have continuous guards and handrails on both sides. Where the width of the stair exceeds 2.2 m, intermediate handrails shall be provided so that no point on the stair is farther than 1 m from the handrails.3.10.6
All exit stairways shall be constructed of materials that conform to the fire resistance requirements of the type of construction of the building, except that solid wooden handrails shall be permitted for all types of construction.3.10.7
An exit stairway shall not be built around a lift shaft unless the enclosure of the lift shaft is solid and made of a material with fire resistance rating required for the type of construction of the building.3.10.8
Exterior staircases used as fire escapes shall not be considered as a means of exit, unless they lead directly to the ground, are separated from the building interior by fire resistive assemblies or walls and are constructed of noncombustible materials.3.11 RAMPS
3.11.1
The minimum width of exit ramps shall not be less than that required for corridors by Sec 3.7.3.11.2
The slope of an exit ramp shall not exceed 1 in 8, but for slopes steeper than 1 in 10 the ramp shall be surfaced with approved non-slip material or finished such as to effectively prevent slipping.3.11.3
Guards or handrails shall be provided on both sides of ramps having slope steeper than 1 in 15.3.12 HORIZONTAL EXITS
3.12.1
The connection between an area of the building which the horizontal exit serves and the area of refuge or another building shall be provided with protected openings in 2 hour fire resistance rated walls, or by open air balcony or bridge.3.12.2
The horizontal exit shall be protected from the area of incidence by self closing type fire door.3.12.3
The width of a horizontal exit shall not be less than 1 m.3.12.4
The slope of the horizontal exit shall not exceed 1 vertical in 10 horizontal. No steps shall be used in horizontal exits.3.12.5
Where the horizontal exit serves as an exit from only one side, all doors shall swing in the direction of escape travel. Where exit from both sides may be required, the doors shall have two leaves opening in opposite directions, or there shall be adjacent doors opening in opposite directions. The doors shall be openable at all times when the building is occupied without the use of a key.3.12.6
The discharge area of a horizontal exit shall be either public spaces or private to the occupants of the building. The capacity of the area of refuge or building on the refuge side shall be computed as the minimum net floor area excluding stairways, shafts etc. The required capacity of refuge shall be 0.28 m² per occupant. In the case of patients confined to bed in hospitals and clinics etc., the required capacity of refuge shall be 2.8 m² per bed.3.13 SMOKE PROOF ENCLOSURES
3.13.1
A smoke proof enclosure shall consist of an interior stairway conforming to Sec 3.10 and an exterior balcony or a ventilated vestibule.3.13.2
All exit stairways serving occupants located more than 23 m above the ground shall be protected by a smoke proof enclosure.3.13.3
There shall be access to the stairways from every storey by way of a vestibule or an open balcony. The minimum width of a vestibule shall not be less than 1.1 m nor less than the width of the corridor leading to the vestibule. The minimum length of a vestibule in the direction of escape travel shall be 1.8 m.3.13.4
The minimum fire resistance rating of the walls separating the smoke proof enclosure from the area of incidence shall be 4 hours with no openings other than the required fire doors for exit.3.13.5
All doors in smoke proof enclosure shall be self closing type or they shall be fitted with automatic closing devices triggered by the fire detection system installed at the floor side entrance to the enclosure. The activation of fire detection system at any door in any floor shall activate the automatic door closers of all the doors at all levels of the smoke proof enclosure.3.13.6
When access to the stairway is through a vestibule instead of an open exterior balcony, the vestibule shall have adequate natural ventilation. Each vestibule shall have a minimum area of opening of 1.5 m² in an exterior wall facing a courtyard, street or public way wider than 6 m.3.14 NUMBER OF EXITS
3.14.1
The requirements of the number of exits specified in this subsection shall apply to buildings of all occupancy groups unless a more restrictive requirement for any occupancy is provided in Chapter 5, Part 4 or elsewhere in this Code.3.14.2
Only one means of exit shall suffice for the buildings specified in Table 4.3.5 provided that they do not have more than one floor below the level of exit discharge.3.14.3
For all other buildings the required number of exits shall depend on the occupant load as specified below:- Occupant load 500 or less: Minimum 2 exits
- Occupant load 501 to 1000: Minimum 3 exits
- Occupant load more than 1000: Minimum 4 exits
3.14.4
All buildings more than 6 storeys or 20 m in height and all buildings having a floor area larger than 500 m² on each floor, used as educational, institutional, assembly, industrial, storage or hazardous occupancy or a mixed occupancy involving any of these, shall have a minimum of two staircases. The staircases shall be of the enclosed type and shall lead directly to the exterior or the designated area of refuge.3.15 LENGTH OF TRAVEL
3.15.1
Exits shall be arranged in such a manner that the travel distance from any point in the area served shall not exceed the following values:- Occupancy A, B, C, D, E, J: 25 m
- Occupancy F, H: 30 m
- Occupancy G: 45 m
3.15.2
Wherever more than one exit are required in a building they shall be placed as remote as possible from each other. As far as practicable, exits shall be arranged in such a manner as to provide refuge to a person irrespective of the direction of travel from any point in the area served.3.16 MEANS OF EXIT SIGNS AND ILLUMINATION
3.16.1
All required means of exit or exit access in buildings or areas requiring more than one exit shall be signposted. The signs shall be clearly visible at all times, where necessary supplemented by directional signs. All exit doors shall be clearly marked for easy identification.3.16.1.1 Location
Exit signs shall be installed at stair enclosure doors, horizontal exits and other required exits from the storey. When two or more exits are required from a room or area, exit signs shall be installed at the required exits from the room or area and where otherwise necessary to clearly indicate the direction of escape. Exceptions:- Main exterior exit doors which obviously and clearly are identifiable as exits need not be signed when approved by the Building Official.
- Exit signs are not required for buildings of Occupancy A1 and individual units of A2.
- No sign is needed for exits from rooms or areas with an occupant load of less than 50 when located within C1, C2 or C3 Occupancy.