Appeal 31680

OSSC 705.11 and 705.11.1.

705.11 Parapets.
Parapets shall be provided on exterior walls of buildings.
Exceptions: A parapet need not be provided on an exterior wall where any of the following conditions exist:

1. The wall is not required to be fire-resistance rated in accordance with Table 705.5 because of fire separation distance.
2. The building has an area of not more than 1,000 square feet (93 m2) on any floor.
3. Walls that terminate at roofs of not less than 2-hour fire-resistance-rated construction or where the roof, including the deck or slab and supporting construction, is constructed entirely of noncombustible materials.
4. One-hour fire-resistance-rated exterior walls that terminate at the underside of the roof sheathing, deck or slab, provided that:

4.1. Where the roof/ceiling framing elements are parallel to the walls, such framing and elements supporting such framing shall not be of less than 1-hour fire-resistance-rated construction for a width of 4 feet (1220 mm) for Groups R and U and 10 feet (3048 mm) for other occupancies, measured from the interior side of the wall.
4.2. Where roof/ceiling framing elements are not parallel to the wall, the entire span of such framing and elements supporting such framing shall not be of less than 1-hour fire-resistance-rated construction.
4.3. Openings in the roof shall not be located within 5 feet (1524 mm) of the 1-hour fire-resistance-rated exterior wall for Groups R and U and 10 feet (3048 mm) for other occupancies, measured from the interior side of the wall.
4.4. The entire building shall be provided with not less than a Class B roof covering.

1. In Groups R-2 and R-3 where the entire building is provided with a Class C roof covering, the exterior wall shall be permitted to terminate at the underside of the roof sheathing or deck in Types III, IV and V construction, provided that one or both of the following criteria is met:

5.1. The roof sheathing or deck is constructed of approved noncombustible materials or of fire-retardant-treated wood for a distance of 4 feet (1220 mm).
5.2. The roof is protected with 0.625-inch (16 mm) Type X gypsum board directly beneath the underside of the roof sheathing or deck, supported by not less than nominal 2-inch (51 mm) ledgers attached to the sides of the roof framing members for a minimum distance of 4 feet (1220 mm).

1. Where the wall is permitted to have not less than 25 percent of the exterior wall areas containing unprotected openings based on fire separation distance as determined in accordance with Section 705.8.

705.11.1 Parapet Construction
Parapets shall have the same fire-resistance rating as that required for the supporting wall, and on any side adjacent to a roof surface, shall have noncombustible faces for the uppermost 18 inches (457 mm), including counterflashing and coping materials. The height of the parapet shall be not less than 30 inches (762 mm) above the point where the roof surface and the wall intersect. Where the roof slopes toward a parapet at a slope greater than 2 units vertical in 12 units horizontal (16.7-percent slope), the parapet shall extend to the same height as any portion of the roof within a fire separation distance where protection of wall openings is required, but the height shall be not less than 30 inches (762 mm).

Permit the existing 3-hour party wall (legacy Area Separation Wall) between two adjacent buildings to terminate above the roof as is, without extending the fire resistance rating 30 inches above the roof as required by 705.11.1.

Proposed Design:
Describe the alternate methods or materials of construction to be used or that exist. (Be as specific and detailed as possible). If this is a Reconsideration of an appeal, enter the original appeal text, followed by a section titled "Reconsideration Text" along with new language.

The project involves alteration of an existing historical building. Literary Arts, Inc. of Portland, Oregon, located in the historical Nathaniel West Building at 719 SE Grand Avenue in Portland, Oregon. This space was used previously as a furniture sales store and will be converted into office, storage and assembly spaces used for engagement of readers, support writings and inspire the next generation with great literature. The building was built in the late nineteenth century and has remained in continuous use since then. The proposed renovations include several improvements that will extend the life of the building, make it safer for its occupants, and reduce the potential fire threat to adjacent buildings.

The building on the south is a single-story structure, its roof is lower than the 2-story Nathaniel West building, the 3-hour party wall continues above that lower roof. The building on the north is about the same height as this building. The existing parapet extends slightly above the roof, and it will be extended some more to ensure adequate insulation and proper drainage.

We request that the height of the 3-hour rated party wall between the buildings be permitted to remain as is, without modification for the following reasons:

1. The building will undergo seismic upgrade per the ASCE 41-BPON as required by City code Title 24.85
2. The building will be fully sprinklered throughout.
3. Automatic smoke detection and audio/visual notification will be installed throughout the building.

The existing building was built in 1892 and has been fully operational for 130 years. The building is located in a historical district and is a contributing structure that adds to the historical charm of this district. None of the buildings in the vicinity have tall parapets, so in its current condition this building matches those rooflines and blends in with the character of the neighborhood.

The owner and Bora architects is working towards listing the building on the National Register. Currently, SHPO has approved the proposal and recommended to the Parks Service that it be listed. OSSC 3405.6 (IEBC section 507) permits historical buildings to be exempted from the requirements of Chapter 34 (IEBC) when approved by the building official. Once the historical listing is complete, this appeal will serve as the approval by building official to allow less than 30 inches of parapet above the roof per chapter 34 of the OSSC.

The party wall is an existing unreinforced load bearing brick. It will be difficult to stack additional masonry units on top of this wall as it will add weight at the top. A lighter wall made of light gage metal stud framing or tube steel framing, will still need to be anchored and braced, which is complicated to design and expensive to build. Even if the parapet was extended 30 inches above the roof, the cost and complexity of construction will outweigh the benefits.

The proposed improvements that include seismic upgrades, smoke detection, and automatic sprinklers, will make the structure more resilient, allow occupants more time to evacuate in an emergency, and control the spread of fire to adjacent buildings.

The thickness of this clay brick wall varies in different locations but it is not less than 6 inches at any location, which makes it more than 4-hour rated per table 721.1(2).This increased rating will provide higher level of protection than what the code intends.

The building has a very small footprint, approximately 3,500 sf per floor, while the allowable area for an A3 occupancy in a Type IIIB construction fully sprinklered building is 38,000 sf. The proposed use of B office and A3 gathering assembly space are considered light hazards occupancies per NFPA 13. The addition of sprinklers to this building will significantly improve the ability to control the spread of fire to adjacent buildings much more than extension of the parapet to 30 inches above the roof. The combination of small size (less than 10% of allowable area), automatic sprinklers, and at least 4-hour fire resistive construction per table 721.1(2) will exceed the code intended protection provided by a 30-inch extension of a 3-hour party wall.

We believe that the proposed improvements will more than compensate for the reduced parapet height and provide a level of safety to the occupants as code intended, while revitalizing a building that is a community treasure. Therefore, we urge you to approve it.