Correspondence •
. -6064
November 23, 2002 CITY OF
OREGON
Roger Superneau
Ankrom Moisan Associated Architects
6720 SW Macadam, Suite 100
Portland, OR 97129
Re: Revised Exiting and Alternate Methods of Construction
Green Office Building, 11560 SW 67
BUP2001 -00061
Dear Mr. Superneau,
We have reviewed the revised exiting plans for the above referenced project as well as
the request for alternate methods of construction. Based on the structural conditions of
moving the stairways and the stage of construction this project is in, we are approving
the alternates subject to the following conditions. This review was performed under the
provisions of the State of Oregon Structural Specialty Code (OSSC), 1998 edition and
the International Building Code (IBC), 2000 edition.
• The current configuration of the exit enclosures does not meet the provisions of
OSSC Section 1004.2.4. The overall diagonal of the building is 114 feet requiring
the exits to be separated a distance of 57 feet. They are currently 32.5 feet apart.
The revised plans show one -hour rated exit passageways on all three floors at
the north end of the building. This puts the required exits approximately 38 feet
apart. You have requested Exception 2 of IBC Section 1004.2.2.1 be utilized as
an alternate which allows the exit separation to be reduced to one -third the
overall diagonal when the building is equipped throughout with an automatic
sprinkler system. One -third of 114 feet is 38 feet. We understand that an
automatic sprinkler system will be installed. The IBC is a nationally recognized
document containing similar provisions as the OSSC. In accordance with OSSC
Section 104.2.8, for alternates, we believe this provides an equal degree of
safety and this request is hereby approved.
• OSSC Section 1005.3.4.4 states that openings into exit passageways shall be
limited to those necessary for egress from normally occupied areas. The revised
• plans show the main floor restrooms opening into the main floor exit
passageway. Due to the hardship of reconfiguring the under -slab plumbing and
to minimize the possibility of compromising the structural footings, you have
requested that we approve an alternate for the existing configuration. Your
proposal' is to construct the walls separating the restroom and exit passageway
with 2 -hour fire - resistive construction with 90- minute doors. These two restrooms
contain only 1 water closet and 1 lavatory each and will only be used by a single
occupant at any given time. In accordance with OSSC Section 104.2.8 for
alternates methods of construction, we believe this provides an equal
degree of safety and this request is hereby approved.
13125 SW Hall Blvd., Tigard, OR 97223 (503) 639 -4171 TDD (503) 684 -2772
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The submitted revised drawings by Ankrom Moisan Associated Architects are approved
subject to the following conditions.
1. All doors opening into the exit passageways and exit enclosures shall be
provided with doors with a maximum transmitted temperature end point not
exceeding 450 F above ambient at the end of 30 minutes of the fire exposure
specified in UBC Standard 7 -2. OSSC 1005.3.3.5, 1005.3.4.4.
2. Penetrations into or through exit passageways are prohibited except for those
serving the exit passageway such as sprinkler piping, standpipes, and electrical
conduit terminating is a listed box not exceeding 16 square inches. OSSC
1005.3.4.4.
3. Penetrations into or through exit enclosures are prohibited except for those
serving the exit enclosure such as ductwork and equipment necessary for
independent stairway pressurization, sprinkler piping, standpipes, and electrical
conduit terminating is a listed box not exceeding 16 square inches. OSSC
1005.3.4.4.
4. Automatic - closing fire assemblies shall have one heat - actuating device installed
on each side of the wall at the top of the opening and one on each side of the
wall at the ceiling height where the ceiling is more than 3 feet above the top of
the opening. OSSC Section 713.2, 713.6.1
5. There shall not be enclosed usable space under stairways or ramps in an exit
enclosure. The open space under such stairways shall not be used for any
purpose. OSSC Section 1005.3.3.6.
6. Exit signs shall be provided and illuminated in accordance with OSSC Sections
1003.2.8 and 1003.2.9.
7. A copy of the approved plans shall be kept on site at all times and made
available for inspection purposes. OSSC 106.4.2.
If you have any questions or concerns, please contact me at (503) 718 -2448.
Sincerely,
Gary Lampella
Building Official
c. Joe Green
Mark Hoyt
Hap Watkins, Supervising Inspector
Jim Hendryx, Director of Community Development
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