Appeal 23802

1021.4

1021.4 Location. Exterior egress balconies shall have a minimum fire separation distance of 10 feet measured at right angles from the exterior edge of the egress balcony to the following:

1. Adjacent lot lines
2. Other portions of the building
3. Other buildings on the same lot unless the adjacent building exterior walls and openings are protected in accordance with Section 705 based on fire separation distance.

The proposed design for an egress balcony within 10' of another building on the same lot is provided equivalent protection by exceeding the requirements of an egress court by providing 1 hour rated walls on each side of the court and 2 means of egress from the egress court.

The Portland International Airport (PDX) is a fully sprinklered building of Type IA construction. Trailers of Type VB construction to be used for no more than 5 years are proposed to be placed 10’-1” from the existing PDX deplaning wall.

The proposed design is for temporary trailers of Type VB, unsprinklered construction to house Port of Portland office functions to exist 10’-1” from the existing terminal building. Egress for ATO-3, ATO-4, ATO-5, and ATO-6 use an exterior walkway as a second means of egress and is closer than 10’ to the existing PDX building wall. The egress balcony will provide equivalent protection for egress as follows:
• The trailers are 10’-1” from the terminal building providing an egress court per 1028.4.2 with 1 hour
rated walls each side.
• The egress court has 2 means of egress to a public way.
• The egress balcony, stair and ramp is of non-combustible construction.

The intent of OSSC 1021.4 is to ensure that occupants can egress out of the building and not be impeded by a fire smoke event. The walls of the trailers facing the existing PDX terminal walls are 1 hour rated as required for a fire separation distance (FSD) of 10’ per Table 602. The existing walls of the PDX terminal at the deplaning level are of CMU construction with 15% openings, exceeding 1 hour fire rating for the wall and less than the 45% of unprotected openings percentage allowed per Table 705.8 with a FSD of 10’. The short egress balcony exceeds the requirements of OSSC 1021.2 for egress court by having 1 hour rated walls and 2 means of egress.

The trailers are of modular wood construction set on the ground without a foundation. The egress for trailer marked ATO-3, ATO-4, ATO-5, and ATO-6 on the attached plan have egress routes going to an elevated walkway adjacent to the existing terminal building. The walkway has been deemed an egress balcony due to it not being at grade level. The balcony serves as a second means of egress and an accessible route to these trailers. The balcony is more than 44” wide and is approximately 6’ from the existing terminal wall. Existing means of egress for the terminal enters into this area as well, with access to a public way in 2 directions.

The means of egress for the existing terminal at grade and for the trailers, elevated above grade, use the egress court created between the buildings. Egress courts per OSSC 1028.4.2 are not required to have fire rated walls where the egress court is more than 10’ wide and not required to have 2 egress routes from them to the public way. The intent of the allowance for non-rated walls is due to the fire/smoke event only occurring on one side of the egress court, and 10’ being enough width for people to move around the escaping heat and smoke to reach the public way. The additional protection measures of fire rated walls on each side of the egress court is to provide protection for egressing occupants to exit the area. Egress courts are not required to have 2 means of egress, intended to provide a single path to the public way only. The proposed egress court has egress to the public way in 2 opposite directions, exceeding code requirements, and providing equivalent protection by egressing occupants not being required to pass by escaping heat and smoke from a fire/smoke event. The proposed trailers will have 1 hour rated walls without unprotected openings facing the existing terminal.

The proposed design of the trailers walls will meet the requirements of Table 602 for 1 hour rating with ¾ rated opening protection. The terminal walls on the deplaning level in this area are of CMU construction, providing more than 1 hour fire rating with unprotected openings meeting the requirements of Table 705.8. The egress court is more than 10’ wide and provides a means of egress to a public way in 2 directions, eliminating the need for egress to pass by escaping heat and smoke. The egress balcony exceeds the code requirements of 1021.2 by providing 1 hour rated wall and protected openings with 2 means of egress. Equivalent protection for egress is provided by the rated wall on each side of the egress court and 2 means of egress from the egress court, therefore request approval of the appeal.