Allowable Floor Area Increase

[Red Stick]

I have an existing 16,000 sf building, VA construction, 'M' use group. The owner wants to add an 8,000 sf steel frame addition with sprinkler (addition will have upholstered furniture) I have 30' perimeter clearance, but how do I handle the allowable increase with partial sprinkler? Also, can I assume the lower value for allowable area from Table 508, type III?

This is in Michigan, using the 2012 Code

Thanks

 

[cda]

how are you doing a partial system?? fire wall??

 

[Red Stick]

I guess that is part of my question. The goal is to make the building to its maximum allowable size. The whole building is use group 'M', 16,000 sf existing. The addition needs to have fire suppression. Does the entire building need sprinklers to take advantage of the increase for sprinklers?

 

[Red Stick]

My mistake, I was referring to Table 503, not 508

 

[cda]

I do know that you cannot have a sprinkler area open to a non sprinkled area

So will this project work with a fire wall or is the business adding retail space to its existing space??

Or is the new space for a completely different tenant

 

[Francis Vineyard]

Red Stick, I believe what cda is referring to is section 602.1.1; unless the addition as you described is separated by a fire wall the construction type for the addition could not be better than 5A. Having steel frame could be constructed as 5B; then the whole building ends up becoming 5B even though the existing is 5A. The answer to your second question in post #3 is yes; sprinkler shall be provide throughout the building according to section 903.2.7

 

[Red Stick]

That is what I thought, thanks

 

[steveray]

If you can construct or convert the adjoining wall as a firewall it should work.....only sprinklering the new "building"....

 

[cda]

If you can construct or convert the adjoining wall as a firewall it should work.....only sprinklering the new "building"....

But say this is an additon to an existing grocery store, the open concept is kind of killed

But if it is an addition to add a new/different/seperate business, to an existing business/building, the fire wall could work

 

[steveray]

Agreed.....If they need it open...

But say this is an additon to an existing grocery store, the open concept is kind of killedBut if it is an addition to add a new/different/seperate business, to an existing business/building, the fire wall could work

 

[RLGA]

So, if your existing area is 16,000 sq. ft. and the addition is 8,000 sq. ft., then the total is 24,000 sq. ft.

Type VA construction for Group M allows 14,000 sq. ft. You say you have 30-foot yards around the entire perimeter. This means you can have a 75% increase to the allowable area.

Thus:

14,000 sq. ft. + (14,000 sq. ft. x 0.75) = 24,500 sq. ft. > 24,000 sq. ft. actual area, therefore, okay.

Why worry about a sprinkler increase?

Additionally, since you're adding the sprinkler per subparagraph 4 of Section 903.2.7, the area will need to be separated by a 2-hour fire barrier per Table 707.3.10. Because if don't, you will be increasing the fire area of the existing Group M, thus, requiring you to comply with subparagraph 1 of Section 903.2.7. If you add the fire barrier, it keeps the existing Group M fire area unmodified, and is therefore not subject to being sprinklered.

 

[steveray]

"903.2.7 Group M. An automatic sprinkler system shall be provided throughout BUILDINGS containing a Group M occupancy where one of the following conditions exists....."

You would have to sprinkler the building not the fire area.....Increase is irrelevant....That's a big negative woodchuck! Unless the fire code allows something different via 903.2.7.1?

 

[RLGA]

Good point, steveray. I missed that.

 

[Francis Vineyard]

So the answer for the OP to have maximum size building without a sprinkler system is an open perimeter single story building of 5A that does not exceed 24,000 sf and divided into fire areas that do not exceed 12,000 sf?

 

[steveray]

Thanks Ron.....It's tough when you are rushing and don't have it all sitting in front of you, I know.

FV.....It does not seem as though there is any exception when you are selling furniture.....See #4

903.2.7 Group M. An automatic sprinkler system shall be provided throughout buildings containing a Group M occupancy where one of the following conditions exists:

1. A Group M fire area exceeds 12,000 square feet (1115 m2).

2. A Group M fire area is located more than three stories above grade plane.

3. The combined area of all Group M fire areas on all floors, including any mezzanines, exceeds 24,000 square feet (2230 m2).

4. A Group M occupancy is used for the display and sale of upholstered furniture.

 

[cda]

"903.2.7 Group M. An automatic sprinkler system shall be provided throughout BUILDINGS containing a Group M occupancy where one of the following conditions exists....."You would have to sprinkler the building not the fire area.....Increase is irrelevant....That's a big negative woodchuck! Unless the fire code allows something different via 903.2.7.1?

I read fire area

I think he is picking up item #4

903.2.7 Group M. An automatic sprinkler system shall be provided throughout buildings containing a Group M occupancy where one of the following conditions exists:

1. A Group M fire area exceeds 12,000 square feet (1115 m2).

2. A Group M fire area is located more than three stories above grade plane.

3. The combined area of all Group M fire areas on all floors, including any mezzanines, exceeds 24,000 square feet (2230 m2).

4. A Group M occupancy is used for the display and sale of upholstered furniture.

So to me if there is a two hour fire wall between the two, only the new has to have sprinklers because of condition 4

 

[RLGA]

I knew I was overlooking something. My original point remains correct. Section 903 of the IBC is applicable to new buildings. Since this is an addition to an existing building, the addition must comply with the current code. Using Chapter 34 of the IBC or the Prescriptive Compliance Method of the IEBC, the code is silent about fire sprinkler systems, but does state that the addition with the existing building is "no less conforming with the provisions of this code than the existing building or structure was prior to the addition." This can be interpreted rather loosely, so the option below would probably work best.

The Work Compliance Method per the IEBC states in Section 1102.3 that "[e]xisting fire areas increased by the addition shall comply with Chapter 9 of the International Building Code." So, if using the IEBC's Work Compliance Method, the code does not require modifying existing fire areas unless they are increased; hence, my earlier position that a fire barrier be installed so as to not increase the existing fire area.

I would say there is room to argue that the existing building does not require a sprinkler system. However, if they want this space open to the existing building, the point is moot and the entire building will need to be sprinklered.

 

[cda]

2012 clean up;;;

4. A Group M occupancy used for the display and sale of upholstered furniture or mattresses exceeds 5,000 square feet (464 m2).

 

[Francis Vineyard]

cda does S-1 work with M?

 

[cda]

cda does S-1 work with M?

Not sure the question

Is it can you call a place selling upholstery and mattresses a S-1

Not if the place is trying not to install sprinklers in my op

 

[Francis Vineyard]

One fire area for selling and display, many more for furniture storage.

FWIW I had been referencing Virginia 2012; deleted #4, thanks for pointing that out.

 

[steveray]

The IEBC....Or as my FM once called it: the "we are all going to die" code.....Good call Ron.....I try not to go there until I am forced....

I would also argue that the "new" addition of upholstered furniture is the trigger for the sprinklers and the ENTIRE building at that time would need to be sprinklered....

 

[RLGA]

I would also argue that the "new" addition of upholstered furniture is the trigger for the sprinklers and the ENTIRE building at that time would need to be sprinklered....

That is very likely possibility, based on local interpretation. The IEBC is very gray on this specific matter.