Ibc 2015 Corridor Continuity Option 4

Here is another great code lesson from our favorite architect contributor Dave Bauer. Confirmed by a Fire Protection Engineer and Code Consultant, this article and attached code references deal with the confusing questions about egress corridors and elevator smoke protection per the International Building Code (IBC). Can you egress through an elevator lobby? Does the occupancy type matter? Do the elevator doors still need to be protected with a cross corridor lobby design? What about the door swing? This post answers these questions and more.

Imagine the condo or apartment plan below. Let's start with the egress path in general. The two red arrows represent the egress paths to the two required stairs. With very few exceptions, two means of egress are required (IBC 2015 Table 1006.2.1). Typically, a single means of egress is allowable for occupancy counts of less than 50, but in residential it's allowable only for occupancy counts of 10 or fewer. Virtually every residential occupancy you will see requires two means of egress (if you want to know why, see the explanation at the bottom of the page). So, for example, if you had to egress from Unit A, you would have the choice of two egress paths, towards project west or project east (terminology architects use to navigate plans). One of those two egress paths are allowed to pass through a lobby, so the path to the stair at project east is allowable (2015 IBC Section 1020.6). If you end the conversation at that point, there is still some important smoke protection missing with a project in this configuration! Read on...

Can you design Unit B as shown? The answer is "NO", because although one means of egress is allowed to pass through a lobby, two are not. IBC 2015 Section 1016.2 stipulates that "one of the required exits shall be provided without travel through the enclosed elevator lobbies required by Section 3006". So then you might flip Unit B such that the door is at the project east side of the unit and outside the elevator lobby. That solves that problem.

Are the cross corridor doors allowable as shown? IBC 2015 Section 1010.1.2.1 requires that with an occupancy count of 50 or greater, doors must open in the direction of egress. If you are egressing from Unit D, your path to the stair at Project East has to pass through Door No. 2, which opens opposite the path of egress. If you flip that door, it would open opposite the path of egress from Unit A. However, if that door were configured like Door No. 1, it would be allowable. This does not inherently create an opportunity for us, but it may not be an automatic task to just put in Door No. 1 in place of Door No. 2. Remember it will take up 6 linear feet of corridor instead of 3, they will have to do it at two locations, and it will require changing the hardware set, which is a big pain in the neck for architects!

So at this point, if the architect were to flip Unit B and were to construct Door No. 2 to match Door No. 1, they would have eliminated the first two issues. But there's no exception to smoke protection along the egress path. So although the lobby may become part of the egress path, that path is still required to be protected. IBC 2015 Section 1020.6 says that "the fire resistance rating shall be continuous for the length of the stairway or ramp and for the length of the connecting corridor on the adjacent floor leading to the exit". The 2015 Commentary further says "the purpose of corridor enclosures is to provide fire protection to occupants as they travel the confined path, perhaps unaware of a fire building up in an adjacent floor area". Consequently, elevator smoke protection would be required at the elevator hoistway opening even if a lobby is part of the egress path.

That's a lot of stuff, but if you think about it all makes sense. Recall that at first glance this condo seemed to be code compliant, and that there was no need for smoke protection at the elevator door. The devil is in the details, so make sure to look at door swings, protected egress paths, and choices of means of egress from any unit. Here's all you need to remember:

1. A residential unit cannot open directly into an elevator lobby. IBC 2015 Section 1016.2
2. Any door interrupting the egress path, must swing in the direction of travel. And in virtually all cases, that direction of travel can be either direction. IBC 2015 Section 1010.1.2.1
3. UL1784 smoke protection is required along the egress path in R occupancies, and although a lobby may be part of that egress paths, the requirement for smoke protection is not waived inside that lobby and the elevators must still be protected. IBC 2015 Section 1020.6

IBC 2015 – Chapter 10 Means of Egress

SECTION 1020 CORRIDORS

1020.6 Corridor continuity. Fire-resistance-rated corridors shall be continuous from the point of entry to an exit, and shall not be interrupted by intervening rooms. Where the path of egress travel within a fire-resistance-rated corridor to the exit includes travel along unenclosed exit access stairways or ramps, the fire-resistance rating shall be continuous for the length of the stairway or ramp and for the length of the connecting corridor on the adjacent floor leading to the exit.

Exceptions:

1. Foyers, lobbies or reception rooms constructed as required for corridors shall not be construed as intervening rooms.

2. Enclosed elevator lobbies as permitted by Item 1 of Section 1016.2 shall not be construed as intervening rooms.

SECTION 1016 EXIT ACCESS

1016.2 Egress through intervening spaces.

Egress through intervening spaces shall comply with this section.

1. Exit access through an enclosed elevator lobby is permitted. Access to not less than one of the required exits shall be provided without travel through the enclosed elevator lobbies required by Section 3006. Where the path of exit access travel passes through an enclosed elevator lobby, the level of protection required for the enclosed elevator lobby is not required to be extended to the exit unless direct access to an exit is required by other sections of this code.

2. Egress from a room or space shall not pass through adjoining or intervening rooms or areas, except where such adjoining rooms or areas and the area served are accessory to one or the other, are not a Group H occupancy and provide a discernible path of egress travel to an exit.

Exception: Means of egress are not prohibited through adjoining or intervening rooms or spaces in a Group H, S or F occupancy where the adjoining or intervening rooms or spaces are the same or a lesser hazard occupancy group.

3. An exit access shall not pass through a room that can be locked to prevent egress.

4. Means of egress from dwelling units or sleeping areas shall not lead through other sleeping areas, toilet rooms or bathrooms.

5. Egress shall not pass through kitchens, storage rooms, closets or spaces used for similar purposes.

Exceptions:

1. Means of egress are not prohibited through a kitchen area serving adjoining rooms constituting part of the same dwelling unit or sleeping unit.

2. Means of egress are not prohibited through stockrooms in Group M occupancies where all of the following are met:

2.1. The stock is of the same hazard classification as that found in the main retail area.

2.2. Not more than 50 percent of the exit access is through the stockroom.

2.3. The stockroom is not subject to locking from the egress side.

2.4. There is a demarcated, minimum 44-inch-wide (1118 mm) aisle defined by full- or partial-height fixed walls or similar construction that will maintain the required width and lead directly from the retail area to the exit without obstructions.

IBC 2015 – Chapter 7 – Fire and Smoke Protection Features

SECTION 701 GENERAL

1010.1.2.1 Direction of swing. Pivot or side-hinged swinging doors shall swing in the direction of egress travel where serving a room or area containing an occupant load of 50 or more persons or a Group H occupancy.

IBC 2015 Table 1004.1.2 specifies occupancy counts for each occupancy type. For residential this number is 200 gross, or for every 200 gross square feet there is 1 occupant. In order to get to 10 occupants therefore you only need 2,000 square feet.

IBC 2012 – Chapter 10 – Means of Egress

SECTION 1004 OCCUPANT LOAD

1004.1 Design Occupant Load. In determining means of egress requirements, the number of occupants for whom means of egress facilities shall be provided shall be determined in accordance with this section.

TABLE 1004.1.2 MAXIMUM FLOOR AREA ALLOWANCES PER OCCUPANT

Thank you for reading. For more information about Smoke Guard and smoke/fire control, visit our website.

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Source: https://www.linkedin.com/pulse/egress-through-lobbies-john-collins?articleId=6442758214005116928

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