1900 SW 4th Ave, Portland, OR 97201
|Status: Decision Rendered|
|Appeal ID: 10400||Project Address: 107 N Cook St|
|Hearing Date: 1/15/14||Appellant Name: Guy Altman|
|Case No.: B-005||Appellant Phone: 503-265-1541|
|Appeal Type: Building||Plans Examiner/Inspector: Peter Drake|
|Project Type: commercial||Stories: 6+ Occupancy: R-2, M, B, S-2 Construction Type: III-A, I-A|
|Building/Business Name:||Fire Sprinklers: Yes - throughout|
|Appeal Involves: Erection of a new structure||LUR or Permit Application No.: 13-225047-CO|
|Plan Submitted Option: mail [File 1] [File 2] [File 3]||Proposed use: Mixed use: apartments/retail/parking|
OSSC Table 503
Table 503 states that A-3 occupancies (roof deck) in Type IIlA construction may not be located higher than 3-stories above grade plane level. (Increases to four stories above grade plane with automatic sprinkler system increase-Section 504.2).
|Code Modification or Alternate Requested|
The proposed design (see attached Exhibit 1-1: Roof Deck Code AnalysisPian) calls for a 5,202 square foot roof deck to occur on the 6th Floor of this building. This deck is for the use of the apartment residents and includes an open seating area (including a natural gas fire pit-see related Appeal), a wood trellis defining a small outdoor kitchenette, a garden area, and a small fenced-off pet area. The open area that constitutes the majority of the "A" occupancy (south of egress path) is 2,455 square feet in area for a total area defined as A-3 of 4,101 gross square feet.
The roof deck has an occupant load of 274 people (see updated figures on Exhibit 1-1), is served by (2) means of egress with, for it's entire length, a well-defined illuminated egress path to (2) two-hour rated stairways (with emergency back up lighting for the path of egress across the length of the roof). As these two stairways descend in the building and penetrate the 3 hour rated occupancy separation at the 2nd floor level, the enclosures become 3 hour rated, thus increasing the degree of protection for those exiting the building. In addition, the building is fully-sprinklered (increasing, as noted above, the number of stories above grade from 3 to 4).
In the event of a fire, the roof deck can be served via fire apparatus from both Cook Street, a fire apparatus access road (and a 60'-0" yard adjacent to this side of the roof deck )-see Exhibit 1-2 Site Plan. See also Exhibit 1-3: Building Section at Roof Deck indicating actual vertical distance of roof deck above grade plane.
The roof deck construction assembly has a one-hour fire rating and is provided with a non-combustible synthetic wood decking at the walking surface.
|Reason for alternative|
Aside from serving as an essential and valuable amenity to the apartment complex, this alternate is required to provide a secure south-facing outdoor space that sits high enough in the building to allow for sunlight to access it when the property across Cook Street to the south is developed (Zoning allows a 100'-0" high building). The location of the roof deck on the 6th floor was also determined by the necessity to stack units below it and by Land Use Review considerations with regards to "stepping down" the facade to the existing residential neighborhood across Cook Street.
By Code, a roof deck is not considered to be a story. Table 503 identifies "Height limitations shown as stories and feet above grade plane". As a deck surface open to the sky, it therefore seems that the primary issue that we are addressing here is providing for the life safety of the 274 occupants using the roof deck that just happens to occur two floors above the Fourth Floor. We believe that we have made equivalent or greater accommodation in the Proposed Design for this alternate which can be summarized as follows:
entire length on both that side and the north side (at the surface parking lot) to fire apparatus.
Type lII-A construction requirements of the Code.
2010 OSSC Table 601& Section 602.3 Type Ill
Table 601 requires 2 hour rated exterior bearing walls for Type lII-A construction.
|Code Modification or Alternate Requested|
In compliance with the Bureau of Development Services' Paul Scarlett's May 13, 2013 directive (attached), buildings of Type 111-A construction may be of non-fire-retardant wood framing with the following conditions:
As part of this application, we would like to obtain approval for using the attached 19/32" thick
Due to yards in excess of 30' on all other sides (including the West and East Interior Courtyard walls which have in excess of a 30' yard in front of them formed by an imaginary property line running down the center of the Interior Courtyard) , this condition applies only to the north wall of the Cook Street portion of the building between Gridlines "D" and "J" along Gridline "6.8". (See attached Exhibit 2-1: Code Analysis Plan for extent of 2 hour and 1 hour rated walls).
B. Exterior bearing walls equal to or greater than 10' from the property line shall be protected on the inside with two layers of 5/8" fire-rated gypsum board and protected on the outside with one layer of 5/8" nominal fire-rated gypsum sheathing over combustible wall sheathing. This comprises a 1 hour rated wall assembly (see attached Exhibit 2-3). In addition, from Applicant's Preliminary Fire Life Safety Meeting (noted above), it was determined that all openings in these one hour rated exterior bearing walls would need to have 3-1/2" minimum solid wood blocking at all head, jamb and sill conditions. Likewise solid blocking for the full depth of the roof or floor member needs to occur at all locations where floor or roof. structure meets these exterior bearing walls.
As part of this application, we would like to obtain approval for using the attached 19/32" thick LP FlameBiock Fire-Rated OSB sheathing in lieu of 5/8" nominal fire-rated gypsum sheathing. Page 6 of the attached submittal identifies UL Listing and applicability for Type Ill Exterior walls.
Due to yards in excess of 30' on all sides (including the West and East Interior Courtyard walls which have in excess of a 30' yard in front of them formed by an imaginary property line running down the center of the Interior Courtyard) , this condition applies to all exterior sides other than the wall plane identified above along Gridline "6.8". (See attached Exhibit 2-1: Code Analysis Plan for extent of 2 hour and 1 hour rated walls).
This project: distance from top of roof parapet to lowest fire apparatus set up point is in compliance. Cook Street meets the Fire Code requirements for fire apparatus aerial access.
|Reason for alternative|
The applicant wishes to replace fire-retardant wood framing with non-fire-retardant wood framing primarily for reasons of cost and constructibility. The costs associated with the City's revocation of Chapter 24.95 "Special Design Standards for Five Story Apartment Buildings" which previously allowed Type VA Construction are substantial.
By employing the aforementioned Code Guide directive from Paul Scarlett, as well as direction from our Preliminary Fire Life Safety Meeting at which we obtained approvable details for similar 5 over 1 projects recently approved by the City, we have provided an equivalent degree of structural capacity, life safety and fire protection. Likewise, the enclosed fire-rated sheathing alternative has been previously approved for use in the City of Portland. We are seeking approval for it's use as defined above.
1. A-3 Roof deck located above the 4th story of the IIIA portion of the building: Granted provided the trellis structure is all non-combustible and has no roof covering. A furniture plan must be provided as part of the permit plan review, and maximum occupant load signage shall be mounted at the deck. This approval excludes the use of the deck for BBQ or other open flame.
Please note: the adjacent recreation room must be sized so it maintains a B occupancy.
2. Alternative to Fire Treated sheathing in IIIA exterior wall construction: Granted as proposed.
The Administrative Appeal Board finds that the information submitted by the appellant demonstrates that the approved modifications or alternate methods are consistent with the intent of the code; do not lessen health, safety, accessibility, life, fire safety or structural requirements; and that special conditions unique to this project make strict application of those code sections impractical.