Exit from stories

[G2arch]

Have a client bought a building currently configured as such.
Occupancy B
Fully Sprinklered
Two Stories at 3500 sf each
Unenclosed stair inside building about 1/3 distance from front of building
Enclosed stair at back of building.

He would like to configure it as such.
First floor stays B. First floor would still have two exits, out front door and out back enclosed stair.
Second floor front 1500sf is B occupancy access only from the open stair.
Second floor back 2000sf is to be an R-2 Dwelling unit access only from enclosed stair.

Jurisdiction current code is IBC 2012.
I can meet the requirements of Table 1021.2(1) for the R-2 dwelling as I am less than 4 dwellings and less than 125 max exit access travel distance.
I can meet the occupant load but not the exit access travel distance Per Table 1021.2(2) for the second floor B occupancy. Maximum Exit access travel distance 75 feet. I can not make it down the stairs and to an first floor exit in this distance. Therefore, am I correct that this configuration will not meet IBC 2012 code?

Second Question, The jurisdiction is considering adopting IBC 2018. IBC 2018 Table 1006.3.3(2) for Stories with One Exit has been changed to read 75ft common path. I can get to the bottom of the open stair in less then 75feet where one would have two ways to go, either the front exit or the back exit. So it does meet IBC 2018 code?

Thanks
Ken

 

[Francis Vineyard]

Table 1021.2(2) footnote b. Group B, F and S occupancies in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 shall have a maximum travel distance of 100 feet.

Though the code sections below specify the travel distance is not a common path of travel towards two (2) exits but to an exit.

1021.3.1 Access to exits at adjacent levels. Access to exits at other levels shall be by stairways or ramps. Where access to exits occurs from adjacent building levels, the horizontal and vertical exit access travel distance to the closest exit shall not exceed that specified in Section 1016.1. Access to exits at other levels shall be from an adjacent story.

1016.3 Measurement. Exit access travel distance shall be measured from the most remote point within a story along
the natural and unobstructed path of horizontal and vertical egress travel to the entrance to an exit.

 

[RLGA]

I suggest going with the code modification to use the 2018 IBC.

Although FV's IBC quotes would seem to indicate that it would be allowable, the terminology used refers to "levels" and not "stories." Section 1021.3.1 would apply when the floor level changes as a building might do if constructed on a sloped grade. Table 1021.2(2) refers specifically to "stories," and the language is "exit access travel," which means it is measured from the most remote point to an exit. If the closest exit is more than 75 feet, then it would not comply.

The 2018 change makes more sense, since the concern is not exit access travel distance, but common path distance, since the building has two exits on the first story.

 

[Francis Vineyard]

Ron, thanks for catching my error, missed the level terminology. The coorect reference would be 1021.2 item 2.

Before your comments I hadn't considered adjacent building levels except for mezzanines.

 

[JBI]

Has the jurisdiction adopted the Existing Building Code?
There would likely be more options there for this existing building that is undergoing a partial change of occupancy.

 

[mtlogcabin]

3401.6 Alternative compliance.
Work performed in accordance with the International Existing Building Code shall be deemed to comply with the provisions of this chapter.

A jurisdiction does not have to adopt the IEBC in order to use it. It is an alternative compliance under chapter 34


Start with the IEBC section 1012.4 since you have a change of use in an existing building. If it is a higher hazard it will send you to the IBC Chapter 10

 

[G2arch]

Thanks for the help! I am going to pursue with the AHJ the use of IBC 2018 code.