Hoistway Opening Protection - An Overview

One of the fundamental concepts of fire protection and life safety in a building is compartmentation - the division of a building into multiple compartments to limit the spread of fire and smoke. The provision of floor assemblies, and specifically fire-resistance rated floor assemblies, is one common example of compartmentation. At the same time, there are legitimate reasons to design openings through these floor separation, such as elevator hoistways. To simultaneously allow for elevator hoistways and maintain some level of compartmentation, the International Building Code (IBC) sets forth requirements for protection of hoistway openings. This post will provide an overview of hoistway opening protection, including when it is required and the various options for how to provide the protection. All code references are to the 2021 IBC.

What is Hoistway Opening Protection? (Not Just Elevator Lobbies!)

As alluded to above, hoistway opening protection is a method to protect openings in hoistways in order to limit the spread of fire and smoke. Historically, this protection has been typically provided by enclosed elevator lobbies, but the code does now provide two other methods for this requirement. 
 
It's important to note that most standard elevator doors are already rated 90 minutes per UL 10C. This rating provides protection against fire spread but does not provide any sealed containment against smoke spread. Therefore, in certain cases, the IBC requires additional hoistway opening protection to limit the spread of smoke. ​

When is Hoistway Opening Protection Required?

The 2021 IBC mandates hoistway opening protection in several scenarios to mitigate the risk of fire and smoke spreading through elevator shafts. Hoistway opening protection is required where an elevator hoistway connects more than three stories and when any of these conditions apply (IBC 3006.2): 

1. The building is not fully sprinkler-protected in accordance with NFPA 13 or 13R. 
2. The building contains a Group I-1, Condition 2 occupancy. 
3. The building contains a Group I-2 occupancy. 
4. The building contains a Group I-3 occupancy. 
5. The building is a high-rise and the hoistway is more than 75 feet in height measured from the lowest floor to highest floor served. 

 
So if a hoistway is connecting more than three stories and meets any of the above conditions, hoistway opening protection is required. There are three exceptions to these requirements: 

1. Hoistway opening protection is not required where the elevator serves only open parking garages. 
2. Hoistway opening protection is not required at the level(s) of exit discharge when those levels are fully sprinkler-protected in accordance with NFPA 13. 
3. Hoistway opening protection is not required on levels where the hoistway opens to the exterior. 

 
Additionally, IBC 3006.2.1 requires hoistway opening protection where hoistways open into a fire-resistance rated corridor. 
 
Other Conditions 
There are a number of other code requirements that could require the provision of an elevator lobby: 

1. Underground buildings (IBC 405.4.3) 
2. Areas of refuge (IBC 1009.6) 
3. Fire service access elevators (IBC 3007.6) 
4. Occupant evacuation elevators (IBC 3008.6) 

 
These requirements are only triggered in certain conditions, so be sure to review the above-referenced code sections for more information. ​

What are the Methods of Hoistway Opening Protection?

The 2021 IBC outlines several methods for protecting hoistway openings, each with its own advantages and specific applications. These methods include (IBC 3006.3): 

1. Elevator Lobby Using Fire Partitions 
2. Elevator Lobby Using Smoke Partitions 
3. Additional Doors at Hoistway Openings 
4. Hoistway Pressurization ​

Let's delve into each method in detail. ​

Elevator Lobby - Fire Partitions 
 
Fire partitions are one of the most common methods for hoistway opening protection. Key aspects of this method include: 

• Fire-Resistance Rating: 1 hour (IBC 708.3) 
• Continuity: From floor below to underside of floor/roof sheathing above, or to underside of a 1-hour floor or roof/ceiling assembly (IBC 708.4) 
• Opening Protectives: 20 minute fire door, self-closing unless exceptions are met, smoke/draft control doors not required (IBC 3006.3 and 716.2.2.1) 
• Duct Penetrations: Fire/Smoke dampers not required if fully ducted system and building is sprinkler protected in accordance with NFPA 13 or 13R (IBC 717.5.4) 
• Joints/Penetrations: Protected with listed firestop assembly (IBC 714.4) 
• Impact on Architectural Design: Moderate to high - lobbies take up physical space that could be used for other purposes 
• Cost Impact: Low - construction of a lobby enclosure is fairly inexpensive 

 
Elevator Lobby - Smoke Partitions 
Smoke barriers are similar to fire partitions but focus primarily on preventing the migration of smoke rather than fire. This method includes: 

• Fire-Resistance Rating: Not required (IBC 710.3) 
• Continuity: From floor below to underside of floor/roof sheathing above, or to underside of a ceiling assembly that is constructed to limit the transfer of smoke (IBC 710.4) 
• Opening Protectives: Non-rated doors, self-closing, smoke/draft control doors required (IBC 3006.3 and 710.5.2.2) 
• Duct Penetrations: Fire/Smoke dampers not required if fully ducted system, smoke dampers required for air transfer openings (IBC 717.5.7) 
• Joints/Penetrations: Sealed to resist the passage of smoke (IBC 714.6) 
• Impact on Architectural Design: Moderate to high - lobbies take up physical space that could be used for other purposes 
• Cost Impact: Low to moderate - construction of a lobby enclosure is fairly inexpensive, however provision and testing of dampers could add to cost 

 
Additional Doors at Hoistway Openings 
Installing additional doors at hoistway openings is another method prescribed by the IBC. This approach involves: 

• Fire-Resistance Rating: Not required (IBC 3006.3) 
• Continuity: Provided at the hoistway opening only (IBC 3006.3) 
• Opening Protectives: Non-rated doors, self-closing, smoke/draft control doors (tested without artificial bottom seal) required (IBC 3006.3 and 716.2.2.1.1) 
• Duct Penetrations: N/A 
• Joints/Penetrations: N/A 
• Impact on Architectural Design: Low - as long as there is room to mount the door assembly in or above the hoistway opening, these doors take minimal space 
• Cost Impact: Moderate to high - these additional doors are typically much more expensive than traditional doors 

 
Hoistway Pressurization 
Hoistway pressurization is a more advanced method for protecting hoistway openings. This involves creating a positive pressure differential between the hoistway and the floor to prevent smoke from entering. Hoistway pressurization is considered a smoke control system per IBC 909.21 and requires the following: 

• Pressure Differential: The system must provide a minimum of 0.1 inches of water and a maximum of 0.25" between the hoistway and the floor (IBC 909.21.1) 
• Rational Analysis: A rational analysis report complying with IBC 909.4 is required to be submitted with the construction documents (IBC 909.21.2) 
• Protection: The ductwork and fan system is required to be protected with the same fire resistance rating as required for the elevator shaft itself (IBC 909.21.3 and 909.21.4) 
• Standby Power: The hoistway pressurization system is required to be provided with standby power (IBC 909.21.5) 
• Acceptance Testing: Special inspections required (IBC 909.18.8) 
• Ongoing Testing: Required semiannually for dedicated systems (IFC 909.22.4) 
• Impact on Architectural Design: Low - hoistway pressurization fans can typically be located on the roof 
• Cost Impact: High - the cost to design and install pressurization systems is often more than the other protection methods ​

Comparing Hoistway Opening Protection Methods ​

While each method of hoistway opening protection has advantages and disadvantages, here are my recommendations: 

1. If you are going with a lobby, use the method which does not require a damper. From a construction standpoint, a 1 hour rated fire partition and a smoke partition are fairly similar. However, the provision of fire and/or smoke dampers adds additional cost and testing requirements that can be avoided.  
2. If no lobby, utilize additional doors at the hoistway. While these additional doors at the hoistway opening can be expensive, they are fairly easy to design, test and maintain. The other option, hoistway pressurization, is considered a smoke control system and comes with substantial requirements both for design and ongoing maintenance. 

Conclusion

The IBC offers four methods for hoistway opening protection: elevator lobbies using either fire partitions or smoke partitions, additional doors at the hoistway openings, or hoistway pressurization. This protection is required in certain instances, depending on the occupancy, presence of sprinklers and height of the building, but is only necessary for hoistways connecting more than three stories or opening onto a rated corridor. ​