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I have an existing 4000 Sq. Ft. building, A-2 Occupancy with an occupant load ~200.  The owner wants to add ~1500 Sq. Ft, with an additional occupant load ~50. 2006 IBC 903.2.1.2 requires a sprinkler system if the area > 5,000 SF and/or if the occupant load > 100.

3403.1 says (1) "Additions shall not be made that will cause the existing building to be in violation of the code."  But it also says (2) "Portions of the structure not altered and not affected by the alteration are not required to comply with the code requirements for a new structure"

The existing building is not sprinklered (it was built before the local municipality had adopted any bulding code).

It appears to me that the addition is "affecting" the existing structure (with regards to the area/occupant load), and the entire building needs sprinklered (#1 above); in fact it doesn't meet the current code as it is (occupant load > 100).  However, it seems that it could also be argued that addition is the only thing that needs to meet the current code (#2 above), and the area and occupant load (of the addition) does not exceed the limits that require sprinklers.

Any opinions?

Thanks in advance,




In my opinion, the owner is increasing the risk by increasing the building area and occupant load. However, the primary function (see IBC section 3402) has not changed so one could argue the sprinkler requirement.

The 2006 IBC was revised to require automatic sprinkler protection when the occupant load is 100 or greater as a result of the Station Fire in Rhode Island. This fire resulted 99 deaths and was caused by improper use of pyrotechnics and poor interior finish materials. I offer this to you because I'm not sure what your use is.

The other part to this question is IBC section 102.1. Your citing a general provision while the requirement for automatic sprinklers is a specific requirement. In this case, section 102.1 requires that when their is a conflict between a general provision and a specific provision, the specific provision governs.

If I was the fire or building code official, I would require the installation of the automatic sprinkler protection.


I recommend you speak to the building official.  My interpretation is the addition must be sprinklered and I would require the service be sized to be extended to the existing building.  

Don Phillips


Chapter 34 mandates that unless the addition and the existing building are separated by a firewall, that the total building must meet whatever code rules, particularly fire and sprinkler rules, that the current code mandates.  So it would sound like the sprinklers would need to be throughout assuming no firewall.


The key is whether you are adding the 1500 sq. ft. addition to the existing building with or without a firewall separating them. If you add 1500 sq. ft. and create a "fire area" over 500 sq. ft. you would have to sprinkle the entire building.
Hope this helps.


5000, rather.

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