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Dull Olson Weekes-IBI Group Architects,Inc.
907 SW Stark Street
lol/ , Portland OR 97205 USA A P r G J/z I) ,q LTA 2 nt a
fax 503 226 6950
fax 503 273 91192 ^
Revised February 3, 2014
January 27, 2014
Mark VanDomelen
Building Official
City of Tigard
13125 SW Hall Blvd.
Tigard, OR 97223
RE: Gym and Commons Exiting @ Westside Christian High School
Dear Mark,
The purpose of this letter is to document our approach for meeting the exiting requirements for
the high school's new gym (currently under construction)and the newly remodeled and
expanded high school.
As earlier stated, it came to our attention that our original exiting calculations contained some
errors. With this letter, we are defining our approach to correct these errors, to bring the building
into conformance with the IBC and to meet your approval.
Attached, you will find a new(revised) spreadsheet that examines the exiting requirements from
the Gym, exit"D" and from the Commons.
Exiting from the Gym was complicated by the client's desire to have a way to secure the rest of
the school from the gym. It was decided to use a coiling door between the Commons and the
Gym to accomplish this goal. This limited the exit width available from the gym's exit"I"to the
double-leaf door(exit"K"). Because exit"I" goes through a fire wall and becomes a horizontal
exit, the capacity of exit"I" becomes limited by the size of Hall 160. Based on the area of Hall
160 and allowing 3 square feet per occupant; the capacity of exit"I" is 283 occupants. By
adding another door leaf to exit"H" (resulting in three door leaves) and given the available
capacity of exit"I", using the refuge area, we believe that the required exiting from the Gym has
been satisfied. Exiting provided for up to 1,563 occupants and calculated occupancy of 1,474,
so exits as proposed are adequate.
The calculation for exit"D" is included to assist in calculating the exit width available for exiting
from the Commons. Based on the exit calculations for the Commons, ate the revision of the
office conference room occupancy count (using 100sf/occ) and the revision of the music
occupancy count(using 50 sf/occ), we have calculated that we are just shy of the required exit
width by less than 4 inches or 18 occupants. To resolve this issue, we propose we post the
. - .:- • -- - - -•- - -- . Because the Commons
the Auditorium are an ancillary use of the school we suggest that the Office and the
Classrooms would not be occupied at the same time as the Commons and Auditorium would be
occupied to capacity. This would reduce the loading on the exits by 157 from the classrooms
and 37 from the office, which would more than offset the exit width we are under as calculated
above and on the attached spreadsheet. We suggest that posting the occupancy of the spaces
(Commons &Auditorium) at 1,265 is a reasonable number.
IBI
GROUP IBI Group is a group of firms providing professional services
Dull Olson Weekes-IBI Group Architects,Inc.is a member of the IBI Group of firms
Dull Olson Weekes•IBI Group Architects,Inc. 2
VanDomelen—February 3,2014
Hopefully this meets with your approval.
Sincerely,
Dull Olson Weekes—IBI Group Architects, Inc.
Norm Dull
Principal
Attachment:
Westside Christian High School Exiting Spreadsheet, February 3, 2014
J:\Prelnt\Westside Christian High School\11015 Westside Christian HS Addition-RemodellGeneral File\Code-Permits-AHJ\14-0203 VanDornelen exiting.docx
Westside Christian High School
February 3, 2014
Gym Exiting
Required Required
Total Width- Width-
Contributing Occupancy Total Width Occupants Totals Multiplier Inches Exit Capacity
Gym 10,307 SF 7 SF/Occ 1,472
Office 152 SF 100 SF/Occ 2
Total Occupancy 1,474 0.2 -
Occupant Load Requires 4 exits
Current Design 4 exits with 12 door leaves
Total width 12 Ivs 32 inches 384 0.2 1,920
However:
There are 3 exits to exterior(exit"H"to be enlarged to 3 leaves)
8 Ivs 32 inches 256 0.2 1,280
Therefore Exit "I" to Commons needs to accommodate
1,474 less - 1,280 equals 194 0.2 39
4 Ivs 32 inches 128 0.2 640
128 inches is greater than the 39 inches req'd.
Because exit"I"goes through a "fire wall" occupants exiting through these doors are considered to have exited the building. There is a
requirement for the area on the other side of the fire wall to accommodate the load from the exit through the fire wall. Below is the refuge area
capacity of the Hall 160 with the coiling grill down forcing exiting through exit K.
Hall 160 915 SF 3 SF/Occ 305 occs for refuge area available
Weights/Fitness 1,094 SF 50 SF/Occ less 22
Total Occupant Capacity from Gym through exit "I" of Hall 160 based on Refuge 283
Area
Total Occupant Exiting Capacity(of exterior doors with 3rd door leaf at exit "H") 1,280 plus 283 for Exit"I"
The exit width needs to serve the exiting needs of 1,474 which is less than 1,563 therefore OK
1:\Prelnt\Westside Christian High School\11015 Westside Christian HS Add ition-Remodel\General File\Code-Permits-AH1\14-0203 Exiting Review
Exit "D"
I
Required Required
Width Width -
Contributing Occupancy Total Multiplier iinches 'Exit Capacity
Classrooms 5,736 SF 20 SF/Occ 287
Music 938 SF 50 SF/Occ 19
Large Group 4
Offices 2
Workroom 2
Total Occupancy 314 0.2 63
Exit Width provided 2 !vs 32 64 0.2 320
We assumed half will go toward Exit"D"and half toward Exit"A". So the occupant load from the identified rooms above toward Exit
"D" and Exit"A" will be 314/2 or 157 each. 157
Remaining exit"D"capacity 163
1:\Prelnt\Westside Christian High Schoo1\11015 Westside Christian HS Additan-Remodel\General File\Code-Permits-AHl\14-0203 Exiting Review
Commons Exiting
Required Required
Total Width Width -
Contributing Occupancy SF SF/Occupant Occupants Multiplier inches Exit Capacity
Stage 988 SF 15 66
Auditorium 2,544 SF 7 363 0.2 73 avail 128" _
Commons 5,850 SF 7 836
Office 1,265
Reception 261 SF 100 3
Conference 161 SF 100 2
Principal 136 SF 100 1
Staff Room 496 SF 100 5
Work Room 417 SF 100 4
Conference 229 SF 100 2
Open Office 1,872 SF 100 19
Conference 78 SF 100 1
37
_.��. .-
Kitchen 625 SF 200 3
Half of Hallway Exiting into
Commons 157
160
Total Occupant Load 1,462
Calculating the Req'd Exit Width
Exit"D" remaining capacity 163
Exit"L" 2 !vs 32 64 0.2 320
Exit"M" 2 lvs 32 64 0.2 320
Exit"A" 4 Ivs 32 128 0.2 640 0.2
Total Exit Capacity F 1,443
Exit Capacity Exceeded 1,462 less 1,443 equals 18
The exiting capacity based on width of doors provided is under what is required for the number of occupants. 1,465 occupants have
been calculated and exit capacity is 1,440 based on door width. The exiting capacity is exceeded (by 1,462 compared to 1,443 or) by
18 people which equates to less than 4 inches of exit width.
J\Prelnt\Westside Christian High School\11015 Westside Christian H5 Addition-Remodel\General File\Code-Permits-AHJ\14-0203 Exiting Review