Building Code Guide 06-10: Fire Sprinklers in R Occupancies

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Source: Building Code Guide 06-10: Fire Sprinklers in R Occupancies ↗ Last modified: Sun, 19 Apr 2026 20:06:24 GMT

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BCG 06-10: Fire Sprinklers in R Occupancies

QUESTION: The Oregon Structural Specialty Code (OSSC) requires an automatic fire sprinkler system to be installed throughout all buildings containing a Residential (Group R) occupancy. Group R occupancies include hotels, apartments, and condominiums. When and where is a fire sprinkler system required in existing buildings that have a Group R fire area added? 

RESPONSE: The following conditions describe when and if a full or partial automatic sprinkler system is required in an existing building that has a Group R fire area added:

Condition 1.

Converting a structure or a portion of a structure from a single-family residence, duplex, or townhouse constructed under the Oregon Residential Specialty Code to any R use classification in the Oregon Structural Specialty Code, including R3 uses:

Automatic sprinklers are required to be installed throughout the entire building.

Condition 2.

Converting a portion of the structure to a use classification other than R occupancy within a building containing an existing R occupancy:

Automatic sprinklers are not required to be installed in existing, unsprinklered buildings containing one or more dwelling units or guest rooms where a portion of the structure is converted to a use classification other than R occupancy, provided all of the following conditions are met:

1. It can be clearly documented by permit records that the building is legally classified as containing R occupancy; 
2. The area being converted to other than R occupancy is not required to be sprinklered by any other provisions of the Oregon Structural Specialty Code based on occupancy classification; 
3. The allowable area, allowable height and type of construction for the building comply with the Oregon Structural Specialty Code without automatic sprinklers, and;
4. Required separations between the R occupancy portions of the building and the portion of the building being converted to a different occupancy are constructed as required by the Oregon Structural Specialty Code.

Condition 3.

Enlarging existing dwelling unit(s) or guest room(s) by adding residential use floor areas converted from adjacent non-residential space within a building. 

Automatic sprinklers may be installed solely in additional residential use floor areas converted from adjacent non-residential space to enlarge an existing dwelling unit within existing unsprinklered buildings, without installing sprinklers throughout the entire building, provided all of the following conditions are met: 

1. It can be clearly documented by permit records that the building is legally classified as containing R occupancy.
2. The additional residential use floor areas are not located three or more stories above grade. Creation of this condition will require the entire structure to be fully sprinklered.
3. The automatic sprinkler system serving the additional residential use floor areas is installed to meet NFPA 13 R standards, to the satisfaction of the Fire Marshal's Office.