3003 W CASINO RD BLDG 45-03 2019-07-15

12-15-05; 9:32AM;BOEING ;4253428167 # 1/ 2 The Boeing Company P.O.Box 3707 Seattle,WA 98124-2207 December 13, 2005 GPNPP-05-1214 Post-it®Fax Note 7677 flare pe°ges► To 'I Fr Co./DeptCo. Tony Lee 1 Phone# Phone# City of Everett Fax# �s-7�9 e Fax# Building Department I 3200 Cedar Street Everett, WA 98201 BOE/A/G BOEING 45-03 BUILDING ALTERATIONS —PROPOSED USE OF IEBC Dear Tony, The City of Everett's adoption of the 2003 IBC does not appear to implement the use of the 2003 IEBC for alterations to existing structures. We request that the City of Everett allow Boeing to use the 2003 !EBC for the structural design portions of the subject building alterations. This change is justified for the following reasons: 1. The total weight of the building (structural+mechanical+electrical+architectural+cranes) is being reduced by more than 3%, from 4640 tons down to 4492 tons. Most of the net weight reduction occurs in the attic area. This reduction will result in a lower overall seismic base shear. The 2003 IEBC does not require an upgrade of the complete lateral force resisting system if the seismic base shear does not increase by more than 5% due to the alterations.. 2. The existing building uses a tension-only lateral force resisting system. This type of system has a poor performance history during design-level events. Per the 2003 IBC, upgrading this system for full conformance to the 2003 IBC is not required if we can show that the seismic stress in existing building structural elements does not increase by more than 5% due to the alterations. This analysis has been completed, with interesting results. If we denote any element with a seismic stress of 5 ksi or less as "lightly loaded," we find the following: Check of Seismic Force Resisting System Element Stresses in Altered Buildin Lightly Loaded Heavily Loaded Total > 1.05 chane 271 95 366 < 1.05 chane 539 162 701 Total 810 257 1067 I