Is Church balcony a mezzanine if it doesn’t open into lobby below? CBC 505.2 and 4

[Yikes]

Proposed church sanctuary, type V, A-3 occupancy, fully sprinklered. Sanctuary is on-grade, balcony is one level above it.

The balcony is open to the sanctuary, and has 2 means of egress (stairs) directly down into the main, on-grade sanctuary. The balcony sits on top of the lobby, but is NOT open to it, because there are doors that separate the lobby from the main sanctuary floor.

A mezzanine is allowed to be 50% of the area of the room in which it is located. CBC 505.2.

Now, the balcony is 65% of the sanctuary area alone, which is too big to call it a mezzanine. B

UT, it is only only 31% of the sanctuary + lobby area combined. So it works, if I count both the sanctuary AND the lobby in my ratio.

QUESTION: Can a balcony this big rightfully called a “mezzanine” if it doesn’t open to the lobby?

Under CBC 505.4 exception 5, a mezzanine doesn’t need to be open to the room in which it is located. Utilizing this, can the lobby therefore be enclosed, but we can still count the lobby with the sanctuary as part of “the room in which it [the mezzanine] is located”?

 

[Msradell]

That's certainly an interesting design with such a large balcony and I'm not quite sure how the codes would interpret it. Most church balconies I've dealt with have at least one exit that goes into the lobby/narthex area and not directly into the sanctuary. I've always thought that was a code requirement but can't find a reference to it. It makes sense because if there was an emergency in the sanctuary the only course of exit from the balcony would be through the sanctuary where the emergency was. If the balcony had a exit into the lobby area I would certainly agree with your interpretation, without that I'm leaning towards saying it isn't. Unfortunately, none of us deal with churches that often so we don't have a lot of experience in that area.

 

[cda]

is it a "Story"?

 

[cda]

2009

1028.5 Interior balcony and gallery means of egress. For balconies, galleries or press boxes having a seating capacity of 50 or more located in Group A occupancies, at least two means of egress shall be provided, with one from each side of every balcony, gallery or press box and at least one leading directly to an exit.

1028.5.1 Enclosure of openings. Interior stairways and other vertical openings shall be enclosed in an exit enclosure as provided in Section 1022.1, except that stairways are permitted to be open between the balcony, gallery or press box and the main assembly floor in occupancies such as theaters, places of religious worship, auditoriums and sports facilities. At least one accessible means of egress is required from a balcony, gallery or press box level containing accessible seating locations in accordance with Section 1007.3 or 1007.4.

 

[Yikes]

cda, if it is not a mezzanine, then it is a "story". So, my first step is to see if it qualifies as a mezzanine.

The bigger picture is this: The client wants to build the sanctuary out of steel (Type II), but they want it to connect up to their Type V Sunday School building without having to do a buildign separation. Therefore they are exploring the idea that the whole thing is Type V. Given the way the area calcs are shaking out, the only way that works is if the balcony is "mezzanine", and therefore not counted as floor area.

 

[zigmark]

Is it possible for the mezzanine to be open to the lobby area? If it is not even capable of being open to the lobby, i.e. the roof over the lobby is to low structurally to even allow it, then it could never be a mezzanine to the lobby. I have had a similar situation and based my determination on that criteria. I would also caution the use of "floor area". Stick with building area or fire area to stay within the code terminology and definitions since there are some signifigant requirements/allowances based on them.

Good Luck!

ZIG

 

[steveray]

505.4 Openness.

A mezzanine shall be open and unobstructed to the room in which such mezzanine is located except for walls not more than 42 inches (1067 mm) high, columns and posts.

Exceptions:

1. Mezzanines or portions thereof are not required to be open to the room in which the mezzanines are located, provided that the occupant load of the aggregate area of the enclosed space does not exceed 10.

2. A mezzanine having two or more means of egress is not required to be open to the room in which the mezzanine is located, if at least one of the means of egress provides direct access to an exit from the mezzanine level.

3. Mezzanines or portions thereof are not required to be open to the room in which the mezzanines are located, provided that the aggregate floor area of the enclosed space does not exceed 10 percent of the mezzanine area.

 

[Yikes]

Probably the easiest way to picture it is that the auditorium / sanctuary is configured similar to a "stadium seating" movie theater. The risers slope upward towars the rear, and at some point the seating is high enough (7' headroom) that the lobby and exit "tunnels" slip in underneath it. At that point, we truly have 2 levels, and the upper one hopefully qualifies as a mezzanine.