Appeal 26285

OFC 507.1

An approved water supply capable of supplying the required fire flow for fire protection shall be provided to premises on which facilities, buildings or portions of buildings are hereafter constructed or moved into or within the jurisdiction. See Appendix D108 “Uniform Alternate Construction Standard for One- and Two-family Dwellings.”

Reduce the fire flow requirement for this building due to low fuel load.

The proposed structure is a replacement for the previous dome, constructed in 2011, and damaged during the 2021 winter storm. At 24,000 sq. ft., the inflatable dome structure is a one-for-one replacement, covering four existing tennis courts located on the Lewis & Clark College.

The structure is within 400 feet of an existing fire hydrant with a flow of 1147 gpm @ 20 psi. Per OFC Appendix B, the required flow rate of a 24,000 sq. ft. type IIB, unsprinklered building is 3250 gpm @ 20 psi residual.

This membrane dome structure is a single story, with a large open floor area and high volume due to the dome. The result is a large open area for covering four tennis courts and a structure with a very low fuel load. The structure meets the membrane requirements of the code, is equipped with a fire alarm system and the egress path is open to clearly signed exits leading directly to the public way. The existing fire hydrant system was deemed sufficient when the dome was replaced in 2011.

Given the fire hydrant flow is an existing condition that served the previously permitted dome, the nature of the membrane structure construction and low fuel load, the existing system meets the intent of the Oregon Fire Code, which has not changed since the previously permitted dome.

OFC 507.5.1

Where a portion of the facility or building hereafter constructed or moved into or within the jurisdiction is more than 400 feet from a hydrant on a fire apparatus access road, as measured by an approved route around the exterior of the facility or building, on-site fire hydrants and mains shall be provided where required by the fire code official.

Approve the use of the existing fire hydrant within 400’ of the building even though it is not located along an approved route.

The proposed structure is a replacement for the previous dome, constructed in 2011, and damaged during the 2021 winter storm. At 24,000 sq. ft., the inflatable dome structure is a one-for-one replacement, covering four existing tennis courts located on the Lewis & Clark College.

The structure is within 400 feet of an existing fire hydrant, but the fire hydrant is not located along an approved route.

This membrane dome structure is a single story, with a large open floor area and high volume due to the dome. The result is a large open area for covering four tennis courts and a structure with a very low fuel load. The structure meets the membrane requirements of the code, is equipped with a fire alarm system and the egress path is open to clearly signed exits leading directly to the public way. The existing fire hydrant system was deemed sufficient when the dome was replaced in 2011.

Given the fire hydrant location is an existing condition that served the previously permitted dome, the nature of the membrane structure construction and low fuel load, the existing system meets the intent of the Oregon Fire Code as the hydrant location is directly adjacent to approved route, and the OFC has not changed since the previously permitted dome.

City of Portland code guide – Emergency and Required Standby Power Systems - OSSC/27/#1 & NEC/7/#1

II.D.2 Natural Gas. Natural gas may only be used as emergency or required standby power supply for elevators required for accessible means of egress and not for other systems. However, natural gas powered CHP/CoGen Systems may be used subject to the following:

a. The CHP/CoGen system may only serve elevators required for accessible means of egress, stair pressurization fans, accessible means of egress elevator pressurization fans, sub-duct fans, and/or atrium smoke control fans, and
b. The building served must be a Risk Category I, II, or III as shown in the OSSC Table 1604.5

Allow Natural Gas to be used as the standby power generator fuel source.

The proposed structure is a replacement for the previous dome, constructed in 2011, and damaged during the 2021 winter storm. At 24,000 sq. ft., the inflatable dome structure is a one-for-one replacement, covering four existing tennis courts located on the Lewis & Clark College.

The structure meets the membrane requirements of the code, the egress path is open to clearly signed exits leading directly to the public way, and the occupant load is limited to 160 people per appeal 26159.

The structure includes a standby generator per OFC 1203.2.15 and OSSC 3102.8.1.1. The generator is fueled by an existing natural gas line, the same service utilized for the generator prior to the 2021 dome damage.

Given the previously permitted dome, which utilized natural gas to power the standby generator, and the limited time required for the small occupant load to exit the domed courts, the previous configuration meets the intent of the City of Portland code guide OSSC/27/#1, which has not changed since the previously permitted dome.