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Code Corner

Hello, and welcome to the Code Corner, a quarterly post containing insights on healthcare design and code requirements through research and experience with multiple agencies. Each post will look at a specific topic and some of the nuances and requirements surrounding it.

Table of Contents

■ July 2022 - Smoke Barriers + Compartments
■ March 2022 - Occupancy 
■ About the Author + Related Insights


July 2022

Smoke Barriers + Compartments

If you’re involved in ambulatory healthcare facilities or hospitals, you have no doubt run across smoke barriers running throughout the building carving out spaces with fire rated separations. Let’s look at why and where smoke barriers need to be maintained as well as some areas where they may be omitted in ambulatory healthcare facilities.

First, smoke barriers are referenced in both the International Building Code (IBC) and NFPA 101 - Life Safety Code (LSC) with specifics construction requirements and limiting factors on aggregate areas. Both codes require smoke barriers to be a minimum 1-hour fire rated assembly that is continuous from the floor slab to the underside of the floor, floor / ceiling assembly or roof above. The use of smoke barriers effectively creates smoke compartments that can be used for defend-in-place strategies or areas of refuge where evacuating occupants is not feasible due to building size, patient acuity level or security reasons related to correctional facilities. Opening protections, such as doors and windows, are also required to be rated appropriately with 1-hour smoke barriers being provided with a minimum 20-minute door assembly and glazing provided as fire protective glass (the size of the glazing will determine certain requirements). Smoke compartments must also be continuous from exterior wall to exterior wall, which is defined as the backside of exterior sheathing. This means special care needs to be taken when interior assemblies interact with exterior cavity walls as shown in the example below.

Wall ratings diagram

Currently, both the IBC and LSC are aligned on the maximum sizes and travel distances related to smoke compartments with 22,500 square feet being the maximum aggregate area and 200'-0" travel distance from any point in one smoke compartment to an adjacent smoke compartment. When laying out smoke compartments it is important to note that ample space needs to be provided within each compartment for the occupants of the adjacent smoke compartment to support evacuation and defending in place. This is listed as 30 net sq ft per inpatient, 15 net sq ft per ambulatory patient or limited care facility patient and 6 net sq ft for stories not housing patients. The tricky point here is to look at the configuration for areas that are accessible during an evacuation event; a large storage room may look appealing for housing many occupants, but typically these rooms are locked, and the hazard of the space would need to be considered if low enough to allow use in this situation. The most common areas used for accumulation space are corridors, patient rooms, treatment rooms, lounges, and open assembly spaces (dining, worship, conference rooms).

For hospitals, smoke compartments are required on every story where occupants receive care, treatment or sleeping occurs;  such stories must be divided into at least two smoke compartments. There is an exception for floors that have less than 50 occupants not requiring space subdivision in both codes, but this is not a common occurrence as the resulting floor area would be roughly 12,000 sq ft. Things get interesting when Business occupancies, such as ambulatory healthcare facilities (AHC), are brought into the mix. Not only are AHC's required to be separated from other non-AHC functions by a 1-hour fire partition (IBC) or a 1-hour fire barrier (LSC), but they also follow similar subdivision of space requirements with smoke compartments like hospitals. 

The IBC and LSC agree that each story of an AHC is required to be divided into not less than two smoke compartments, but LSC has a few additional exceptions that allow a lessened approach.  Per LSC, if an AHC is less than 5,000 sq ft and is equipped with a smoke detection system smoke compartments would not be required. The IBC does not have this exception but does offer AHC facilities less than 10,000 sq ft per story (cumulative of all AHC’s on a single story) to have smoke compartments omitted, which LSC also agrees with, provided the facility is equipped with an automatic sprinkler system (which is required per 422.4 in the IBC). For example, the life safety plan below indicates a business occupancy that is divided into a clinical and ambulatory healthcare facility.  The separating wall is serving two functions: one - providing the required 1-hour fire barrier, per LSC, between the AHC and other tenants/occupancies, and two - the required smoke barrier to divide the story into not less than two compartments. Since the AHC is more than 10,000 sq ft the space did not qualify for the omission of smoke compartments but does allow for adjacent occupancies to be utilized as a smoke compartment and as a compliant means egress per the IBC 422.3.1 and LSC since the construction type remained the same and a similar level of protection was provided.

Life Safety Plan

Floorplan occupancy

Recently, I had the privilege of reviewing a facility with Joint Commission and the surveyor raised the question of why we had shown separations between a hospital and a business occupancy clinic as a 2-hour smoke barrier. Surprised by the question, I replied with the answer "It's the boundary of the smoke compartment, shouldn't it be continuous around the aggregate area?" The surveyor noted that his survey only stops at 2-hour fire barriers and not 2-hour smoke barriers while directing me to the LSC which gives exceptions to where smoke barrier subdivisions do not apply, as shown below, and referenced subsection (2): The smoke barrier subdivision requirement of shall not apply to any of the following:

(1) Stories that do not contain a health care occupancy located directly above the health care occupancy
(2) Areas that do not contain a health care occupancy and that are separated from the health care occupancy by a faire barrier complying with
(3) Stories that do not contain a health care occupancy and that are more than one story below the health care occupancy
(4) Stories located directly below a health care occupancy where such stories house mechanical equipment only and are separated from the story above by 2-hour fire resistance-rated construction
(5) Open-air parking structures protected throughout by an approved, supervised automatic sprinkler system in accordance with Section 9.7

The surveyor was not wrong, and I had learned something new, but something was still off to me as a 2-hour smoke barrier is constructed identical to a 2-hour fire barrier and I requested the evening to contemplate the requirements before making a sweeping change to this facility’s life safety plans. That evening, I reviewed the IBC as well and could not find any reference where a smoke compartment boundary could be shown as a fire barrier in lieu of a smoke barrier; rather, I found the opposite as shown below, calling for smoke barriers to provide a boundary for separating smoke compartments:

709.4.1 Smoke-barrier walls separating smoke compartments. Smoke-barrier walls used to separate smoke compartments shall form an effective membrane continuous from outside wall to outside wall.
To completely separate smoke compartments within a building, the horizontal continuity of the smoke barrier walls must extend from exterior wall to exterior wall.

The other caveat was that the surveyor had referenced Chapter 18 of the LSC, which is for new construction. The area he was reviewing would have fallen under Chapter 19 of the LSC for existing healthcare spaces, which does not have the same exception to provide a fire barrier in lieu of a smoke barrier. Sharing my findings with the surveyor the following day he indicated that they do not survey for the code enforced in each municipality (IBC 2009 from the last renovation in our case), rather to NFPA 101 - LSC. We came to the agreement that it would be in the facility’s best interest to show the wall with both a 2-hour fire barrier and 2-hour smoke barrier to alleviate any future disagreements.

Understanding all aspects of smoke barriers and compartments can have great implications on patient safety in the event of an emergency and a big impact on maintenance of a facility going forward.  In the next edition of Code Corner we'll dive into elevator lobbies and when they should be provided.

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March 2022


When efficiency is paramount and maximizing adjacencies is a high priority, choosing the right location for your next healthcare project becomes one of the most important decisions when starting design. With many types of visits and procedures moving to outpatient settings, understanding the requirements of mixed-use occupancies has the potential to be one of the largest impacts on the cost of construction in a project and should be considered early in the process. Collocating various types of facilities into a single building has its advantages, but can also be difficult to achieve depending on the type of use and occupancy. On a recent surgical expansion to an existing hospital, future flexibility was key. With changes coming to reimbursement models and insurance companies encouraging more procedures be performed in outpatient settings the separation requirements were above and beyond what is minimally required for the occupancy today. 

Starting with building requirements in Wisconsin, the International Building Code (IBC) 2015 and NFPA 101 - Life Safety Code 2012, each outline minimum hourly rating requirements to be provided between varying occupancies. Referring to the IBC, Table 508.4 indicates the required separations between different occupancies. The most common occupancies in a healthcare setting are I-2 (Hospital), B (Business) and S (Storage). There is the possibility that A (Assembly) spaces are incorporated in the form of conference centers, training rooms, worship spaces and dining areas, but those will be discussed a little later when accessory occupancies are addressed. As most of us are accustomed to, Hospitals are mostly separated from other occupancies by 2-hour fire rated construction, so the focus of this article will largely be on other types of separations.

TABLE 508.4

Table 508.4 Required Separation of Occupancies (Hours)

S = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.
NS = Buildings not equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.
N = No separation requirement.
NP = Not permitted.
a. See Section 420.
b. The required separation from areas used only for private or pleasure vehicles shall be reduced by 1 hour but not to less than 1 hour.
c. See Section 406.3.4.
d. Separation is not required between occupancies of the same classification.
e. See Section 422.2 for ambulatory care facilities.

The separation selection does not stop with the table above. As you can see there are multiple footnotes that can apply to various types of facilities, mainly sub note "e" which notes an additional requirement for ambulatory care facilities above and beyond the fire ratings noted here. Digging deeper into sub note "e" in Section 422.2, you would find that ambulatory care facilities that treat four or more patients who are incapable of self-preservation are required to be separated from other spaces not associated with the primary use by fire partitions, even when the table above may not require it (ex. Business occupancy clinical space to Business occupancy ambulatory care facility does not require a fire separation by Table 508.4, but the additional requirements in 422.2 would).

Switching gears to the requirements of NFPA 101, the starting point for discussion is Table, which is more restrictive than the IBC at first glance, but looking into the dagger notes, allows for reductions in fire separation requirements when a sprinkler system is present in some situations. The same ambulatory care facility, now called ambulatory health care in NFPA, requires a 1-hour fire separation to other business occupancies, which is more restrictive than the IBC, plus there is no mention of the use of fire partitions (this term does not exist in NFPA) in the separation requirements, so a more robust 1-hour fire barrier is required. And because we've dug this far already and can't put the shovel down, the requirements of the State Operation Manual for Ambulatory Surgical Centers carries provisions for a minimum of a 1-hour fire separation between ASCs and other occupancies, but for the sake of this discussion we will not go into the Code of Federal Regulations Title 42.

As mentioned above, there are times when additional occupancies will be present within the primary building. A typical use is assembly spaces, which come with their own challenges in terms on higher occupant loads, exit quantities and egress distance separation. Most model codes require a fire separation between Assembly spaces and other uses, but taking advantage of these spaces as an accessory to the main use typically avoids requirements for fire separation. The IBC states that an accessory use must be less than 10% of the aggregate floor area it is present on; this can be very helpful in buildings with large dining spaces. Within the accessory area you can take advantage of the code requirements for that particular occupancy, but there is a potential tripping point if NFPA 101 applies to your building:

508.2.3 Allowable building area.The allowable area of the building shall be based on the applicable provisions of Section 506 for the main occupancy of the building. Aggregate accessory occupancies shall not occupy more than 10 percent of the floor area of the story in which they are located and shall not exceed the tabular values for nonsprinklered buildings in Table 506.2 for each such accessory occupancy.

While the accessory occupancy use is only found in the IBC, NFPA 101 does have language to allow these types of spaces to coexist without a fire separation so long as the occupancies meet the more restrictive portions of the code per NFPA 101 (2012) - Mixed Occupancies. There is no quantitative limit provided in NFPA, so the limitations have the potential to be left up to the Authority Having Jurisdiction (AHJ): Mixed Occupancies.     Each portion of the building shall be classified as to its use in accordance with Section 6.1.*   The Building shall comply with the most restrictive requirements of the occupancies involved, unless separate safeguards are approved.

Getting the proper occupancy separation can be a daunting task depending on the building’s particular use and construction type, but early planning can ensure that future adaptations of built space can take place with maximum reuse and minimal reconstruction efforts. The previously mentioned surgical expansion is currently part of the I-2 Occupancy Hospital, but was provided with a 2-hour fire separation in lieu of a more typical 1-hour smoke barrier for multiple reasons. The first was to allow the surgical center to be flipped to an ASC without the need for renovation (the expansion met the requirements for hospital construction), second to provide a horizontal exit between the two spaces, and third was to provide separation to a multi-story lobby to avoid the requirements of an atrium. While the cost may have been higher upfront, the future flexibility to avoid disruptive renovations proved to be the right move for the facility. Stay tuned for next quarter’s discussion on smoke compartments and a very interesting interpretation I've encountered while on a survey with Joint Commission.

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Nick Gates, RA, NCARB
Senior Project Architect : Associate

Nick Gates, RA, NCARB, is a Senior Project Architect and Associate with EUA. He works out of the Milwaukee office as a member of the Healthcare Studio. When he's not in the office, Nick likes to golf and work on cars.