Upcoming changes in NBC 2016 Part 4 ANNEX E (Clauses 5.1.4 & 6) E-4

Upcoming changes in NBC 2016 Part 4 ANNEX E (Clauses 5.1.4 & 6) E-4 

As on date 16-09-2025, latest version of NBC 2025 still not released. This post is tentative / draft only. Latest version of NBC 2025 is applicable for existing buildings when they are altered (see clause 5.1.4 and 6) or in the opinion of the authority constitute a hazard to the safety of the adjacent property or to the occupants of the building itself or are unsafe. Below Writeups is proposed only.

ANNEX E indicate ADDITIONAL REQUIREMENTS FOR HIGH RISE BUILDINGS

E-1 GENERAL (No Changes in upcoming NBC 2025)

E-2 EGRESS AND EVACUATION STRATEGY (No Changes in upcoming NBC 2025)

E-3 FIRE SAFETY REQUIREMENTS FOR LIFTS (No Changes in upcoming NBC 2025)

E-4 HORIZONTAL EXITS AND REFUGE AREA (Changes in upcoming NBC 2025)

E-5 ELECTRICAL SERVICES (No Changes in upcoming NBC 2025)

E-6 FIRE PROTECTION (Changes in upcoming NBC 2025)

E-7 FIRE AND LIFE SAFETY AUDIT (Changes in upcoming NBC 2025)

E-8 HELIPAD (No Changes in upcoming NBC 2025)

High rise buildings (15 m and above in height) shall receive special attention with respect to fire and life safety particularly with regard to planning, design, execution, maintenance and training so that the intended provisions of this Code are well implemented.

Horizontal Exit

Horizontal exits are a type of exit that protect occupants from the effects of fire without requiring vertical travel, such as within a stairwell. In some cases, they don’t even require occupants to exit a building.

So, its A way of passage from one building to an area of refuge in another building on approximately the same level, or a way of passage through or around a fire barrier to an area of refuge on approximately the same level in the same building that affords safety from fire and smoke originating from the area of incidence and areas communicating therewith.

Looking more closely at above definition, it is clear that there are two different types of horizontal exits. The first provides safety in another adjacent (often attached) building, while the second type provides safety in the same building, on the same level, using a fire barrier. So there is minimal elevation change and a fire barrier provides the separation between the area where the fire is and the area of safety. The construction of the horizontal exit must meet fairly specific design criteria.

Typically, horizontal exits are permitted provided other types of exits are also available. For compartments utilizing horizontal exits, at least half of the number of exits and half of the egress capacity required from that compartment must be provided by other types of exits. In the example below, two exits are required from each area and the horizontal exit and exit stairs are sized to accommodate the same number of people.

Areas A and C meet the requirement for at least half the required exits to be a component other than a horizontal exit. They each have a stair. Additionally, since they are sized the same, at least half the capacity also comes from a component other than a horizontal exit. Area B, on the other hand, does not meet that requirement, since the only exits available are the door in horizontal exit 1 and the door in horizontal exit 2. Therefore, a stair would need to be added so that occupants in area B have access to at least one exit that is not a horizontal exit. Then, the requirement for at least half the required number of exits and egress capacity would come from an exit other than a horizontal exit. The second horizontal exit would be permitted to remain, since it isn’t required—it would be seen more as a convenience door.

In order for a horizontal exit to be credited as an exit, there must be a path continuously available that leads from each side of the exit to stairways or other means of egress that lead outside of the building. If either side of the horizontal exit is occupied, the door leaves used in connection with the horizontal exit must be unlocked from the egress side.

Where a horizontal exit is used, the floor area on either side of the horizontal exit must be sufficient to hold the occupants of both floor areas. There must be at least 3 ft² (0.28 m²) clear floor area per person. In the example below, the horizontal exit is in the middle of the floor. Each side has 67 occupants. This results in a total occupant load of 134. This means that each side of the horizontal exit must have 402 ft² (122.5 m²) of clear floor area for the accumulation of occupants.

67 occupants + 67 occupants = 134 occupants
134 occupants x 3 ft²  = 402 ft²
134 occupants x 0.28 m² = 37.52 m²

The horizontal exit is required to be a fire barrier with a minimum 2-hour fire resistance rating, unless otherwise permitted for bridges serving as horizontal exits. The barrier must be continuous to the finished ground level. The image below shows this concept. 

The barrier does not need to extend below the lowest level that provides discharge to the exterior if the stories below do not have a horizontal exit and are separated from the level above by a minimum 2-hour fire resistance–rated construction. The image below details this concept. The basement level is separated from the remainder of the building by 2-hour fire resistance–rated construction and does not have a horizontal exit.

Similarly, the fire barrier serving as a horizontal exit is not required on other stories provided 1) the stories not containing the fire barrier are separated from the story with the horizontal exit by construction having a minimum fire resistance rating at least equal to that of the horizontal exit fire barrier; 2) vertical openings between the story with the horizontal exit and the open fire area story are enclosed with construction having a fire resistance rating at least equal to that of the horizontal exit fire barrier; and 3) all required exits other than horizontal exits discharge directly to the outside unless the building is protected throughout by an automatic sprinkler system. 
The image below shows this concept. The 2-hour fire resistance–rated fire barrier serving as a horizontal exit is only provided on the top floor. The level of exit discharge and the top floor are separated by 2-hour fire resistance–rated construction. Additionally, the exit stair enclosures are enclosed with 2-hour fire resistance–rated construction even though they only connect three stories.

Typically, doors in the horizontal exit must be swinging type doors that have a minimum 90-minute fire protection rating. In some situations, horizontal sliding doors may be permitted. Fire door assemblies in horizontal exits must be self-closing or automatic closing. For other than approved existing door assemblies, cross-corridor door assemblies in horizontal exits must be automatic-closing doors. Self-closing doors are not an option, which prevents the dangerous, but common, practice of wedging doors open.

The door leaf must swing in the direction of egress travel. For other than sleeping room areas in detention and correctional occupancies, where the horizontal exit serves as an exit for areas on either side of the fire barrier, and the opening is protected by a pair of swinging door leaves, the door leaves must open in opposite directions. There must be an exit sign on either side of the horizontal barrier identifying which door leaf swings in the direction of egress travel from that side. Instead of providing door leaves that swing in the opposite direction, door assemblies may be of any other approved arrangement, provided that the door leaves always swing with any possible egress travel.

A minimum 2-hour fire resistance–rated barrier is still required for bridges that serve as horizontal exits between buildings. The barrier must extend vertically from the ground to a point 10 ft (3,050 mm) above the bridge or to the roofline, whichever is lower. It also must extend horizontally at least 10 ft (3,050 mm) beyond either side of the bridge. For other than approved existing bridges, all openings in the fire barrier must be protected either with fire door assemblies or by a fixed fire window assembly that has a ¾-hour fire protection rating. This helps limit the risk of the bridge being exposed to fire conditions occurring inside the building. 

Bridges must be at least as wide as the door opening to which it leads, and new bridges must be a minimum of 44 in. (1,120 mm) wide.

Upcoming draft NBC part 4 annex E-4 HORIZONTAL EXITS says

E-4.1 Horizontal Exit

A horizontal exit shall be through a fire door of 120min rating in a fire resistant wall. Horizontal exit require separation with the adjoining compartment through 120min fire barrier. The adjoining compartment of the horizontal exit should allow unlocked and ease of egress and exits for the occupants using defend in place strategy.

Requirements of horizontal exits are as under:

a) Width of horizontal exit doorway shall be suitable to meet the occupant load factor for egress.

b) Doors in horizontal exits shall be openable at all times from both sides.

c) All doors shall swing in the direction of exit travel. For horizontal exits, if a double leaf door is used, the right hand door leaf shall swing in the direction of exit travel.

REFUGE AREA

The capacity, in inches, of means of egress stairways shall be calculated by multiplying the occupant load served by such stairways by a means of egress capacity factor of 0.3 inch (7.6 mm) per occupant. Where stairways serve more than one story, only the occupant load of each story considered individually shall be used in calculating the required capacity of the stairways serving that story.

An area of refuge is defined as “either (1) a story in a building where the building is protected throughout by an approved, supervised automatic sprinkler system and has not less than two accessible rooms or spaces separated from each other by smoke-resisting partitions; or (2) a space located in a path of travel leading to a public way that is protected from the effects of fire, either by means of separation from other spaces in the same building or by virtue of location, thereby permitting a delay in egress travel from any level.”

Purpose and Function

·        Temporary Shelter:

Provides a safe haven for people to wait for help when they cannot use elevators or stairwells during an emergency. 

·        Life Safety:

Helps prevent loss of life by providing a secure area away from immediate danger, such as smoke and flames. 

·        Crowd Control:

Prevents overcrowding in escape routes like stairwells, ensuring their functionality for emergency services. 

·        Ventilation and Smoke Control:

Designed to allow airflow, preventing smoke from accumulating and keeping the air breathable. 

Key Characteristics

·        Location: Typically found in high-rise buildings, often at intervals of every 7 floors or 24 meters of height. 

·        Accessibility: Easily accessible from the floors they serve via an accessible means of egress. 

·        Construction: Built with fire-resistant materials. 

·        Ventilation: Open to the outside air on at least one side, often protected by railings, and not locked windows. 

·        Non-Commercial Use: Prohibited from any commercial or residential activity. 

·        Communication: May include communication systems like intercoms or emergency call buttons.

Additionally, two-way communication ( standalone Fire Telephone System to communicate emergency command centre) systems are required in areas of refuge. The exact location of the systems will depend on what is being used as an area of refuge. The system itself, though, needs to allow for communication between the elevator landing and either the fire command center or a central control point that has been approved by the authority having jurisdiction (AHJ). Directions outlining how to use it, how to request help using the system, and written identification of the location all need to be posted next to the two-way communication system. One key component of determining what can be considered an area of refuge is whether or not the building is protected throughout with an automatic, supervised sprinkler system.

Upcoming draft NBC part 4 annex E-4 REFUGE AREA says

E-4.2 Refuge Space/Area

a) Refuge spaces and areas are provided for occupants staging requirements and also enabling assisted evacuation.

The aspect of staging and refuge requirements shall be planned in the building for people with disabilities and ailments, including specific assistance required for certain section of occupants based on their age and other challenges for self-evacuation.

b) Refuge area shall be achieved by adequate planning and consideration of space provided in the lift lobby of fire fighting shaft, enabling the staging for such occupants and further assisted evacuation through fireman lift in the fire fighting shaft. This shall enable these occupants to be assisted evacuated by the lift and further to be brought to exit discharge through the well-planned evacuation strategy through exit passageway on the ground or level of exit discharge. Provision for such staging of the occupants shall be minimum 12m² or 5% of calculated occupants of the floor (served by that firefighting shaft) with a refuge area space of 0.45m² per person in the fire fighting shaft Lift lobby, whichever is higher.

c) Alternatively, refuge area shall be provided in buildings of height more than 24 m. Refuge area provided shall be planned to accommodate the occupants of two consecutive floors (this shall consider occupants of the floor where refuge is provided and occupants of floor above) by considering area of 0.3m² per person for the calculated number of occupants and shall include additionally to accommodate one wheelchair space of an area of 0.9 m2 for every 200 occupants, portion thereof, based on the occupant load served by the area of refuge or a minimum of 15m², whichever is higher, shall be provided as under:

1) The refuge area shall be provided on the periphery of the floor and open to air at least on one side protected with suitable railings.

2) Refuge area(s) shall be provided at/or immediately above 24m and thereafter at every 15m or so. The above refuge area requirement for D-6 occupancy requirement shall however be in accordance with 6.4.2.2.

3) A prominent sign bearing the words 'REFUGE AREA' shall be installed at the entry of the refuge area, having height of letters of minimum 75mm, and also containing information about the location of refuge areas on the floors above and below this floor. The same signage shall also be conspicuously located within the refuge area.

4) Each refuge area shall be ventilated and provided with first aid box, fire extinguishers, public address speaker, fire man talk back, and adequate emergency lighting as well as drinking water facility.

5) Refuge areas shall be approachable from the space they serve by an accessible means of egress.

6) Refuge areas shall connect to firefighting shaft (comprising fireman's lift, lobby and staircase) without having the occupants requiring to return to the building spaces through which travel to the area of refuge occurred.

7) The refuge area shall always be kept clear. No storage of combustible products and materials, electrical and mechanical equipment, etc shall be allowed in such areas.

8) Refuge area shall be provided with adequate drainage facility to maintain efficient storm water disposal.

9) Entire refuge area shall be provided with sprinklers.

10) Where there is a difference in level between connected areas for horizontal exits, ramps of slope not steeper than 1 in 12 shall be provided (and steps should be avoided).

NOTE — Refuge area provided in excess of the requirements shall be counted towards FAR

High rise apartment buildings with apartments having balcony, need not be provided with refuge area; however, apartment buildings without balcony shall provide refuge spaces or area as given above. When refuge areas are preferred over refuge spaces in apartment buildings of height above 60m while having balconies shall be provided at 60m and thereafter at every 30m. The refuge area shall be an area equivalent to 0.3m² per person for accommodating occupants of two consecutive floors, where occupant load shall be derived on basis of 12.5m² of gross floor area and additionally 0.9m² for accommodating wheel chair requirement or shall be 15m², whichever is higher.

Any doors providing access to the area of refuge must have a sign. The area of refuge sign must read “AREA OF REFUGE,” display the international symbol of accessibility, have a nonglare finish, and have letters that contrast with the background. The sign(s) must be illuminated. Tactile signage is also required at each location. Additional signs are required wherever necessary to clearly indicate the direction of travel to an area refuge and at every exit not providing an accessible means of egress. The image below is an example of an area of refuge sign; however, tactile signage would also be required.

Another key aspect of an area of refuge is the presence of wheelchair spaces. Each area of refuge needs to have one wheelchair space that measures 30 inches x 48 inches (760 mm x 1220 mm) for every 200 occupants the area of refuge serves. The wheelchair spaces are not permitted to infringe on the required width of the means of egress for the occupant load served and must never reduce the width to less than 36 inches (915 mm). Each wheelchair space must be accessible without having to pass through more than one adjacent wheelchair space.

Reference:-
CED 46(26992) WC - Draft Code for Comments Only.
NBC 2016 Part 4.
NFPA 101 2024 clause 7.2.4 for more information

About Author:

Dr. Arindam Bhadra is a Fire safety consultant  & ISO Auditor based in Kolkata, India, with over 20 years of experience in Fire safety systems. He’s currently founding director of the Sprinkler Fire Safety Awareness and Welfare Foundation & SSA Integrate. He working on Fire Safety awareness, training, consultancy & Audit in same field. Dr. Arindam Bhadra is popularly known as "Fire ka Doctor" because of his expertise in fire safety, prevention, and awareness, helping people and organizations stay safe from fire hazards. He is Member of FSAI, NFPA, Conformity Assessment Society (CAS) etc. He is certified fire Inspector and certified Fire Protection professional.