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NAZ55 (Electrical) (OP)
29 Apr 09 13:02
We are expanding a control building and a question came up about adding an additional door to meet certain codes and requirements.

I am not much familiar with building design codes and wanted to see if you all could guide me in the right direction.

1- Is there a code requiring how many doors one need based on the size of the building?

2- Is there a code requiring how far the two doors should be from each other? and if so, how far?

3- Any other requirements that I need to be aware of? such as a need for fire extinguishers etc if the building is above a certain size.

I will appreciate comments from some of the experts here.

Helpful Member!  stookeyfpe (Specifier/Regulator)
29 Apr 09 13:11
I'll help you but I need some information. Please respond to the following questions.

1) What is the area of the building?
2) How much area is occupied by equipment and how much area is occupied by people?
3) Is this building one story in height? If not, please indicate the number of levels above and below the grade.
4) Is the building protected by an automatic sprinkler system that is designed and installed in accordance with NFPA 13.
NAZ55 (Electrical) (OP)
29 Apr 09 13:27

Building is a substation Control Center

1) What is the area of the building?
Ans: 25' x 57'

2) How much area is occupied by equipment and how much area is occupied by people?
Ans: half of the area is occupied by equipment the other half is usually empty except for during regular inspections.

3) Is this building one story in height? If not, please indicate the number of levels above and below the grade.
Ans: one story

4) Is the building protected by an automatic sprinkler system that is designed and installed in accordance with NFPA 13.
Ans: No sprinklers  
stookeyfpe (Specifier/Regulator)
29 Apr 09 14:43
Thanks for the information. Based on the information I determined the following using the 2006 edition of the International Building Code.

1. The building is classified as a Business (Group B) occupancy.
2. The function of the space is an industrial area which has an occupant load factor of 100 square feet/occupant (Section 1004.1.1).
3. Based on the building area the occupant load is 7 persons.
4. Only one door is required for exit access. The door must have a minimum width of 32 inches. Panic hardware is not required (Sections 1015.1 and 1008.1)
5. The maximum exit access travel distance is limited to 200 feet. (Section 1016.1.1)
6. Exit illumination and an illuminated exit sign are required. This can be in the form of any method of lughting provided you provide a minimum 1 foot-candle illuminance at the walking surface. (Section 1006.3 and 1008.4)

That's the basics. If you need something more advanced let me know.
NAZ55 (Electrical) (OP)
29 Apr 09 16:09


Are there any NFPA codes I need to comply with also?

stookeyfpe (Specifier/Regulator)
29 Apr 09 19:52
The equivalent requirements are found in NFPA 101. However, both NFPA 101 and the IBC utilize the same method for establishing means of egress requirements.
NAZ55 (Electrical) (OP)
29 Apr 09 20:57
Thanks stookeyfpe you have been very helpful
Arsnman4 (Specifier/Regulator)
21 May 09 19:17
2nd opinion (not that Mr. Stookey needs one) from a NFPA enforcer; he is correct on all counts.

"Fire suppression is a failure in prevention"

NAZ55 (Electrical) (OP)
13 Jul 09 17:30

After further view I have a couple more questions on this.

1- NFPA 101 ( suggests that common paths of travel in general industrial and special purpose industrial occupancies shall not exceed 50 ft, or else we need two means of egress. Since the building in question is longer than 50 ft doesn't that require having two access doors?

Also, if it does require two access doors then wouldn't apply?

I will appreciate the comments.

stookeyfpe (Specifier/Regulator)
13 Jul 09 20:03
How are you measuring your common path of travel? Common path of travel is the distance one travels to get to the point of exit discharge. It's not a simple x to y cannot exceed 50 feet.

Do you have a rudimentary floor plan that you can draw up so I have something to look at?
NAZ55 (Electrical) (OP)
14 Jul 09 9:28
stookeyfpe (Specifier/Regulator)
14 Jul 09 12:29
As I understand the original question, about half of the building is filled with equipment. However, for the purpose of this discussion, I think it is important to understand the purpose and intent of the term Common Path of Egress Travel.

The purpose of this provision is to limit the travel distance when only a single path is available to the building user as a means of egress. It's analagous in my mind to a dead end corridor. The intent of the NFPA 101 and the IBC provisions is that in most cases a common path of egress travel is based on two separate and distinct paths of egress travel toward two or more exits.

The individuals writing the code recognize that their are certain building uses that represent such a fire hazard that they almost always require two exits - conversely, we know from fire loss history that in most instances buildings with a smaller area provide an inherently easier means of egress.

In the case of your building, you technically have only have one point of exit discharge (the West doors). The North door can be used but it cannot be treated as a component in the egress system because its location does not meet 1/2 of the diagional of the exit travel distance - that's OK under the common path of travel provisions.

I'm not sure what the Life Safety Code requires but under the IBC we previously classified the building as a Group B occupancy. IBC Section 1014.3 allows the common path of travel in Group B occupancies to 100 feet or less. Given your previously calculated occupant load, only a single door is required and its width is adequate.

Did that help answer the question?
NAZ55 (Electrical) (OP)
14 Jul 09 13:40

According to Life safety Code (NFPA 101) Table 40.2.5 it appears that Dead End Corridor and Common path of travel can not exceed 50 ft for the facility I described.

Since Life Safety Code is more stringent in this case then I would think it would apply.

Don't you agree?

stookeyfpe (Specifier/Regulator)
15 Jul 09 0:09
Yes. The solution to your problem is to make the North (top of drawing) door a minimum 32 inch door. No panic hardware would be required.
NAZ55 (Electrical) (OP)
15 Jul 09 21:05
Thanks stookeyfpe I appreciate you confirming my thoughts.
We are actually putting another door close to the SE site because of the ease of moving panels in and out through that door and location, since the other sides are not as readily accessible for that purpose.

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