Upgrading a corridor's fire-rating relative to work area.

[Ryan Schultz]

In a renovation, with the following 'work area', where we have to upgrade a corridor wall to 1hr rated, would approach (1) work, or would we have to do (2)--that is upgrade the entire corridor wall to 1hr?



How about in the 2nd image, with a more internal work area? Would we have to upgrade the entire corridor wall to 1hr? Or could that corridor wall remain unrated?

 

[RLGA]

Is the work area completely within the tenant area? Does the work area involve a change of occupancy?

If the answers are 'yes' and 'no,' respectively, then I would say that the corridors could remain as they currently are per IEBC Section 805.2, Exception 2.

This would be a Level 2 Alteration, and if the occupant load does not increase, or if it does increase and the capacity of the egress components are sufficient to handle it, then there is no no "distinct hazard to life."

 

[Ryan Schultz]

Yes, it is 'yes' and 'no'.

Per that exception 2, it seems like I'd want to verify with the AHJ code official, to get the ultimate ruling, correct?

2. Means of egress conforming to the requirements of the building code under which the building was constructed shall be considered compliant means of egress if, in the opinion of the code official, they do not constitute a distinct hazard to life.

 

[RLGA]

Yes, you would have to get a decision from the code official, so do not hang your hat on the concept until you discuss it with them first. And if they agree, GET IT IN WRITING!

 

[steveray]

Don't forget that it is really only in play if it is in the work area AND "shared egress" in level 2

SECTION 804
MEANS OF EGRESS
804.1 Scope. The requirements of this section shall be
limited to work areas that include exits or corridors shared
by more than one tenant within the work area in which Level
2 alterations are being performed, and where specified they
shall apply throughout the floor on which the work areas are
located or otherwise beyond the work area.

 

[Ryan Schultz]

Just reporting back. I just heard back from our AHJ, and they agreed, per IEBC Section 805.2, Exception 2, the corridor doesn't need to be rated.
Thank you again @RLGA and @steveray.

 

[JPohling]

seems as if we may be missing some information? Does this improvement require the corridor now serve more than 30 occupants wher it did not previously?

 

[RLGA]

seems as if we may be missing some information? Does this improvement require the corridor now serve more than 30 occupants wher it did not previously?

If the alteration increased the occupant load anywhere within the work area, then that would be a change of use, and compliance with IEBC Chapter 10 would apply.

For example, if they created a classroom for adult education (less than 50 occupants), it would still be a Group B occupancy, but the use has changed that created "a change in application of the requirements of this code." Even then, IEBC Table 1011.4 shows that there is no change in relative hazard, so compliance with Chapter 10 of the IBC would not apply, except that corridor doors would need to comply with Level 2 Alterations, Sections 805.5.1, 805.5.2, and 805.5.3.

However, if the occupant load of the new classroom example was 50 or more, then it would definitely be a change in occupancy to a higher hazard per IEBC Table 1011.4 (Group B to Group A-3). Thus, the corridor would be required to comply with Chapter 10 of the IBC.

 

[steveray]

If the alteration increased the occupant load anywhere within the work area, then that would be a change of use, and compliance with IEBC Chapter 10 would apply.

I could support that if a "threshold" were crossed, but to call any remodel that adds a person a COU is a little strong....

 

[RLGA]

I could support that if a "threshold" were crossed, but to call any remodel that adds a person a COU is a little strong....

Changing office configuration does not change occupant load since it is based on gross floor area; thus, the exception in Section 805.2 would apply. However, adding a classroom as in my example would, in my opinion, be a change of occupancy according to the definition in the 2018 IEBC. However, as a change of occupancy, the end result is pretty much the same as that for a Level 2 Alteration. An insignificant increase in the occupant load (i.e., a large storage room is converted into a few offices) would not, in my opinion, trigger a change in occupancy (or use).

The 2021 IEBC defines things even more narrowly. A change of occupancy in the 2021 IEBC also includes "[a]ny change in purpose of, or a change in the level of activity within, a building or structure." Conducting adult education, as per my example, would be a change in the level of activity.

 

[JPohling]

lets say the improvement to the office area was to replace 4 private offices with a conference room. conference room still less than 50, but now the occupant load of the suite area being modified requires the non rated hallway to serve more than 30 occupants. The corridor would need to be rated

 

[steveray]

Changing office configuration does not change occupant load since it is based on gross floor area; thus, the exception in Section 805.2 would apply. However, adding a classroom as in my example would, in my opinion, be a change of occupancy according to the definition in the 2018 IEBC. However, as a change of occupancy, the end result is pretty much the same as that for a Level 2 Alteration. An insignificant increase in the occupant load (i.e., a large storage room is converted into a few offices) would not, in my opinion, trigger a change in occupancy (or use).

The 2021 IEBC defines things even more narrowly. A change of occupancy in the 2021 IEBC also includes "[a]ny change in purpose of, or a change in the level of activity within, a building or structure." Conducting adult education, as per my example, would be a change in the level of activity.

See...I would be more flexible here...I can have a classroom or storage room in my office building and convert to offices, or vice versa, and not call it COO if it is not significant in either direction...But that is case by case and most people are not comfortable with that....

 

[JPohling]

I would not call remodeling offices into a "B" conference room a change in use. I would call it an increase in occupant load that will be using the corridor and if it exceeds 30 that corridor is going to become rated. Lets say you have an existing office suite and a new user comes in that is now a conference center /deposition suite. lots of offices that are now meeting rooms. none large enough to be an "A". My gross area did not change. I would not calculate that occupant load based upon the gross area at 1/150.