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Aron Faegre,AIA,PE 520 SW Yamhill Street Portland Oregon 97204 (503)222-2546 FAX/222-6529 faegre�aearthlink.net Alternative Methods Appeal for Yellow Gate Corporate Hangar Echo,Aurora Airport November 5,2015 A. Code Section for which alternative method being proposed: 412.4.1 Exterior walls. Exterior walls located less than 30 feet from lot lines or a public way shall have a fire-resistance rating not less than 2 hours. Proposed Design: • New Hangar Echo: This is a Type 11-13 construction Group III hangar per Table 412.4.6 and does not require fire sprinklering. Section 412.4.1.2 requires a 2 hour east wall on the east wall because it is less than 30 feet from the adjacent 30 foot wide public way. In lieu of the 412.4.1 2 hour wall proposed alternative is: fire water sprinklers at 0.25 gpm higher sprinkler standard for 100%of the building, and NFPA 13 Section 11.3.3 Water Curtain on the east wall of Echo Hangar. Describe Reason for Alternative: • Existing 30 ft easement and fire lane on east side of building, combined with sprinklers provide equivalent alternative. • The new hangar is to be constructed to Type II-B fire safety with fire water sprinklering to the higher standard of OSSC 412.4.6 Exception 2 even though the higher standard is not required. Describe Why, How, etc. the Proposed Alternative is Equivalent and Meets the Intent of the Code in Terms of"Strength, Effectiveness, Fire Resistance, Durability, Health, and Safety": • Our work with the State Building Codes and State Fire Marshal's office has confirmed that fire sprinklering of hangars, and constructing them of non-combustible materials, is the most important method of maintaining fire safety in hangar developments. Copies of surveys of hangar fires(attached) supports this. B. Code Section for which alternative method being proposed: Table 602: 2 hr walls when separation is less than 5 ft. Proposed Design: • New Hangar Echo: This is a Type I1-B construction Group III hangar per Table 412.4,6 and does not require fire sprinklering. Table 602 requires a 2 hour wall on the west wall [ of Hangar Echo and a 2 hour wall on the adjacent existing east wall of Hangar Charlie, �r because the separation to an assumed property line between them is less than 5 feet. In lieu of Table 602 2 hour wall proposed alternative is: fire water sprinklers at 0.25 gpm