Appeal 32392

2022 OSSC Definition of Fire Separation Distance; 2022 OSSC 705.5 – Fire-resistance ratings

FIRE SEPARATION DISTANCE. The distance measured from the building face to one of the following:

1. The closest interior lot line.
2. To the centerline of a street, an alley or public way.
3. To an imaginary line between two buildings on the lot.

The distance shall be measured at right angles from the face of the wall.

705.5 Fire-resistance ratings.
Exterior walls shall be fire-resistance rated in accordance with Table 601, based on the type of construction, and Table 705.5, based on the fire separation distance. The required fire-resistance rating of exterior walls with a fire separation distance of greater than 10 feet shall be rated for exposure to fire from the inside. The required fire-resistance rating of exterior walls with a fire separation distance of less than or equal to 10 feet shall be rated for exposure to fire from both sides.

Allow measurement of the fire separation distance from the building face to a no-build easement line between the new and existing buildings where a shared driveway is located allowing unprotected openings on the exterior walls per Table 705.8.

Reconsideration for appeal 32330 held for more information.

The Pepsi B apartment building located at the corner of Oregon St and NE 25th Ave in Portland has 5 stories of Type IIIA construction over 3 stories of Type IA construction and will be equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 (NFPA 13).

The existing vehicle access driveway off NE Oregon Street serves the adjacent Splash Apartments (aka Pepsi Phase 1A) located at 875 NE 27th Avenue, Portland, OR 97232. This vehicle access driveway is also intended to serve the new Pepsi B building at NEC / Oregon St at NE 25th Ave. A cross easement will be recorded for vehicle access to the Pepsi B garage across the Splash Apartments property by the Owner of 875 NE 27th Avenue. The latter to also record a no-build easement agreement on their parcel between the two building sites so that the new line can be used to measure fire separation distances for both buildings. The positioning of the new fire separation distance line would have no impact on fire resistance rating of exterior walls or allowable area of wall openings of the existing building.

See Fire and Life Safety plans on sheets G2.22 to G2.24, partial Site Section 1/G2.30, partial Exterior East Elevation 2/G2.30 and Site Plan 1/A1.01 on Exhibit A for more information.

Reconsideration Text:
The fire separation between the easement line and the existing building to the east will be established as greater than 20’. For the exiting building permitted under OSSC 2019, per Table 705.8 a fire separation distance between 20 to less than 25 feet allow for Unprotected openings in a sprinklered building to be unlimited. Further with regard to exterior wall rating, where the existing building is I-A/III-A any exterior loadbearing walls would have been provided a minimum fire rating of 3hr/2hr respectively, meeting the OSSC 2019 table 602 minimum rating for 10 to 30’ separation of 1 hour and per table 602, footnote g, any non-loadbearing walls allowed unlimited unprotected openings would require a 0hr rating.

See New Exhibit B – Exiting Building Drawings, including FLS narrative with the existing building’s construction type and code criteria, and elevational information. More information can be referenced via it’s permit documentation under permit 20-129170-000-00-CO. Exhibit A has been revised to clarify the extent of easement and new fire separation distance to the existing building.

The property line between the two lots was originally established to encompass and allow completion of the driveway and its storm-water components in the construction of Splash Apartments at 875 NE 27th Avenue. Portions of the new Pepsi B building’s exterior walls are less than three feet from the existing property line. Section 705.8 and Table 705.8 of the Oregon Structural Specialty Code prohibit openings in exterior walls on buildings within three feet of a property line but allow openings limited to 45% of wall area within 15 feet of a property line.

Reconsideration Text:
The minimum requirements for the existing building as noted in the proposed design are met by default by virtue of meeting its originally permitted code requirements and no changes would be required to the existing building. No unprotected opening area calculation is required for the existing building elevation because the allowed is unlimited.