1330 ROCKEFELLER AVE MEDICAL OFFICE BLDG BASE FILE 2018-01-01 MF Import

i The NBBJ Grou ,uso��,.3�k��,s�«�� "`�� Scanle,Washinglan981P7 �nleiiorOesgn 12(IC>1223�5555 Planning Tcic.32'J7730ur9ess-Sca Emnom¢s Par12W1G2L2300 Cos�htana9emem GmO��c DCSign Landscape�rchnecium July 12, 1988 General Hospital of Everett Job No. Z4077.00 � � Mr. Ren Edwazds I Plans Examiner City of Everett Public Works Depaztment 3200 Cedaz Street Everett� WA 98201 Deaz Ben: This letter is in response to your question: Ho�v does erit�ng from the entry lobby and tLe Medical Office Building for Geaeral Hospital of Everett fimction? The entry lobby is located on the north side of the MOB and is a four-story space that is separated from the rest of the MOB and from the pazking gazage with a 2-hour rated wall. The Lobby is open to four floors with bridges on the three upper floors and a stair that connects the ground� first and second floot. The lobby space is an "Accessory L1se" per Section 3302 of UBC but still requires exit in case of a fire. Those exits are at each floor and back inta the the Main titOB or in:o the Pazking Gazage. The doors can swing either way since the Lobby is not a hazazdous area nor is the occupancy load over 50. Occupancy load for the lobby would be: Ground at 13� First Floor at 10� Second Floor at 8� and Third Floor at 7. We consider the Lobby as a vertical shaft per UBC 1706 and it is enclosed with 2-hour walls from the rest of the MOB and the Pazking Gazage. All penetration thru those walls aze thru doors that aze 1-1/Z hour rate�i and aze connected t� the fire alazm system. The vertical �haft enclosing the lobby also encloses elevators Nos. 1 and 2 that open into that Lobby. We .ealize that this is ;a somewhat unique configuration but there is nothing in UBC preventing t.his configuration providing the shaft meets the requirements oF Section 1706. The obvious question is why is this not an atrium under UBC 1715. The reason being the vertical open area is not lazge enough to be an atrium with a clear l0' diameter for the full height of the atrium. H'e pay a premium to treat it as a shaft since we aze required to have a 2-hour separation in lieu of 1-hour but that is somewhat offset by no requirt�ment for smc,;ce control other than thru the elevator. We feel this is a good approach to this type of space since there is very little occupancy of the space and that Lhere is dmple existing of the MOB through other routes.