TravisMack
Mechanical
- Sep 15, 2003
- 1,757
I thought I generally had a handle on these modifications. Well, as much as a sprinkler guy can. But, I had an interesting conversation with a local plan reviewer in a very large jurisdiction. I think they are mistaken, but I am willing to admit I could be wrong on this.
Here is the project information:
Occupancy: R-2
Construction Type: V-A
Stories: 3
Area per Floor: ±16,000 sq ft
Total Area: 48,022 sq ft
I(f) = 0.75
I(s) = 0
This gives him an allowable area per floor of 21,000. He is using only the frontage allowance to get the area needed for the building. Per my understanding, this would be totally acceptable and the fire sprinkler system could be a 13R system. They are not using the sprinklers to eliminate draft stopping or anything else. Sprinklers are being provided because the jurisdiction has a zero sq ft law. The modified fire code for the jurisdiction has section 903.3.1.2. It is not saying that you can't have a 13R system.
This particular project has about 15 buildings on site. There are 2 of them that are large enough where the sprinkler increase was required and those are protected per NFPA 13. The remaining buildings on site are indicated to be protected by a 13R system per the architect. The plan reviewer is stating that ALL buildings must be an NFPA 13 system. Here is his reasoning.
The plan reviewer claims you have to stop at the end of the section I underlined. He states that since we don't have an NFPA 13 system, the architect can't use the frontage allowance or any other increase. I tried to state that you don't stop reading right in the middle of the paragraph. Because we have a Group R building, we can use the sprinkler system for the height increase. You can also still go to section 506 to do the area increases.
Essentially, it seems that the reviewer is stating you can only use the frontage and/or sprinkler increase if you have an NFPA 13 system. I have always understood it to be that you can use either frontage or sprinkler system increase. You can use both of them if desired to add it up. If you get a full frontage increase and use the sprinkler increase, you could get ±45000 sq ft per floor of a Group R, Type VA construction building.
Travis Mack
MFP Design, LLC
"Follow" us at
Here is the project information:
Occupancy: R-2
Construction Type: V-A
Stories: 3
Area per Floor: ±16,000 sq ft
Total Area: 48,022 sq ft
I(f) = 0.75
I(s) = 0
This gives him an allowable area per floor of 21,000. He is using only the frontage allowance to get the area needed for the building. Per my understanding, this would be totally acceptable and the fire sprinkler system could be a 13R system. They are not using the sprinklers to eliminate draft stopping or anything else. Sprinklers are being provided because the jurisdiction has a zero sq ft law. The modified fire code for the jurisdiction has section 903.3.1.2. It is not saying that you can't have a 13R system.
This particular project has about 15 buildings on site. There are 2 of them that are large enough where the sprinkler increase was required and those are protected per NFPA 13. The remaining buildings on site are indicated to be protected by a 13R system per the architect. The plan reviewer is stating that ALL buildings must be an NFPA 13 system. Here is his reasoning.
504.2 Automatic sprinkler system increase. Where a building is equipped throughout with an approved automatic sprinkler system in accordance with Section 903.3.1.1, the value specified in Table 503 for maximum building height is increased by 20 feet (6096 mm) and the maximum number of stories is increased by one. These increases are permitted in addition to the building area increase in accordance with Sections 506.2 and 506.3. For Group R buildings equipped throughout with an approved automatic sprinkler system in accordance with Section 903.3.1.2, the value specified in Table 503 for maximum building height is increased by 20 feet (6096 mm) and the maximum number of stories is increased by one, but shall not exceed 60 feet (18 288 mm) or four stories, respectively.
The plan reviewer claims you have to stop at the end of the section I underlined. He states that since we don't have an NFPA 13 system, the architect can't use the frontage allowance or any other increase. I tried to state that you don't stop reading right in the middle of the paragraph. Because we have a Group R building, we can use the sprinkler system for the height increase. You can also still go to section 506 to do the area increases.
Essentially, it seems that the reviewer is stating you can only use the frontage and/or sprinkler increase if you have an NFPA 13 system. I have always understood it to be that you can use either frontage or sprinkler system increase. You can use both of them if desired to add it up. If you get a full frontage increase and use the sprinkler increase, you could get ±45000 sq ft per floor of a Group R, Type VA construction building.
Travis Mack
MFP Design, LLC
"Follow" us at
