Appeal 7706

1604.5.1 Multiple Occupancies

Where a building or structure is occupied by two or more occupancies not included the same occupancy category, it shall be assigned the classification category of the highest occupancy category corresponding to the various occupancies.

4310 Macadam is an existing 4 story, 39,000 SF steel framed office building originally constructed in 1982. The building was constructed as a data processing center for The Oregon Bank, now Bank of America, and was used for this purpose until the mid-2000's. The building is notable due to the presence of a large 3,860 SF concrete vault on the ground floor. The vault was constructed with 18 inch thick steel reinforced concrete walls, floors, and ceilings. The building is fully equipped with a functioning automatic fire sprinkler system and smoke detection system and was designed to accommodate a 100 PSF Floor Live Load on the elevated second, third and fourth level office floors. In 2009, KPFF Consulting Engineers performed a seismic evaluation of the structure and determined it to be compliant with ASCE 31standards.

In 2010 the building owner secured a long-term lease with the General Services Administration for the purposes of co-locating two Department of Homeland Security agencies associated with Immigration and Customs Enforcement (ICE). A 71,000 SF building addition comprised of Group S-2 Parking and Group B Office uses was designed to meet the additional ICE program requirements. Permit documents for the reinforced concrete and steel frame addition and alterations to the existing building were submitted for Building Permit plan review in the fall of 2010. (For reasons of construction efficiency two permit applications were made: a structural frame, foundation and underground utilities package was submitted in November 2010; the full building permit submission was made in January 2011.) The building addition structure - also fully fire sprinklered and equipped with automatic smoke detection - was designed to be structurally independent of the existing building so as to not trigger a full upgrade of the existing structure to current seismic and design requirements. As an office and parking structure, the addition was designed as an Occupancy Category II and an Importance Factor of 1.0 applied to the building.

The ICE building program includes a Processing Center where individuals are temporarily detained and interviewed by Federal officers for the purposes of determining their legal status as a resident of the United States of America. While present in the facility, persons of interest are detained in secure holding cells under the constant supervision of ICE officers. They are held for no longer than 12 hours and in no case remain overnight.

The project received approval from the City of Portland Design Review Commission in November 2010. The land use decision was appealed to City Council on the basis that project Use was incorrectly determined by BDS staff. In February 2011 Portland City Council determined that in addition to the Office use the project should be include Retail and Detention uses.

Section 308.4 defines Detention Centers as a Group I-3 occupancy. Table 1604.5 assigns an Occupancy Category of III for Group I-3 occupancies. Category III occupancies have an Importance Factor of 1.25.

Based on the proportionally small size of the Processing Center when compared to the overall building - both in terms of area and use - the proposed design seeks to isolate the ground level Group I-3/ Occupancy Category III from the remainder of the Group B building above through the development of a 1-hour fire rated Horizontal Assembly located in the interstitial space between the vault lid and second floor structure. The proposed design will evaluate and provide necessary modifications to the Processing/ Detention Center structure as necessary to comply with the higher lateral design requirements. The proposed separation would be achieved using any of the means allowed in OSSC Section 712. Please reference the attached building section diagram for the location of the proposed separation.

This proposal also provides an additional means of safety for individuals needing to exit the Processing Center through the construction of a 1 hour fire rated horizontal exit corridor. This new corridor would extend directly from the Processing Center to the exterior thus ensuring occupants a clear, direct egress route from the building that does not require the use of other building exit routes. Please reference the attached Ground Level plan diagram for the location of the egress route. Additionally, as described in the attached letter from the Department of Homeland Security, ICE Office of Co-Location dated , ICE emergency and public safety plans include provisions where in the event of an emergency any detainee present in the Processing Center would be restrained and then escorted by Federal law enforcement officers to either the Sally Port for transportation away from the building - or in the event vehicles are unable to be used to the Public Way.

Approval of the proposed separation of the small Group I-3 occupancy from the larger and more predominant Group B and S-2 occupancies does not reduce the life safety and fire protection requirements for the building occupants. This alternate proposal seeks to balance the needs for occupant safety in the event of emergency against the real space, operational, and financial realities of the project.

As designed, the new structure and existing buildings meet or exceed OSSC lateral requirement for a typical office building. The total proposed building area is approximately 110,000 SF. Of that, 61,000 SF would be used as Office and 45,000 SF for Parking. The remaining +/- 4,000 SF are attributed to the Processing/ Detention use. Considering that this use is proposed to be located inside an 18 inch thick former bank vault that provides a greater level of safety than that required for new Group I-3 facilities a greater or equivalent level of safety for that use is provided. The very location of the Use in the basement of the existing building does not impact the structural or life safety capacity of either the new or existing structure. The materials used inside the Processing Center are non-combustible and the space will be equipped with automatic fire sprinklers throughout.

It appears the intent of the code requirement is to require buildings with mixed occupant categories to have more robust lateral system due to the fact that the occupants in the Category III occupancies are unable to freely exit the building in the event of an emergency. Having a less resilient structure above or below a facility that contains individuals unable to freely exit the building presents an unsafe condition. Hence the code section requires a uniform upgrade of the entire structure to provide emergency personnel adequate time to enter the building after an event and escort those people safely out of the building. In this instance a greater or equivalent level of safety is maintained due to the fact that any person being detained in the Processing Center is under continuous supervision by a Federal law enforcement officer who will escort the person out of the facility to a place of safety. Furthermore, the proposal will provide a horizontal occupancy separation between the Processing/ Detention use and a direct, 2 hour fire rated egress route out of the building that is independent from the routes used by other building occupants.

Lastly. the financial impact associated with complying with the code requirement presents an enormous cost impact to the developer. Based on engineering estimates the increased cost to upgrade both the existing and new building as a result of reinforcing and increasing the structural lateral system amounts to almost $1,000,000. This would make the financing for project unfeasible. Considering that the area classified as a Detention Center comprises just over 2 percent of the total building, the real cost in with applying the code standard an unnecessary burden.

For these reasons, we believe the proposal to separate the Processing/ Detention Center from the rest of the building provides an equivalent level of life safety and structural protection for all the building occupants. Balancing the operational policies that will protect human life in what is proportionally a very small piece of the building program is a prudent use of material and financial resources while in no way reducing the Code requirements for the design of lateral systems.

For these reasons, we respectfully request the Board approve our Appeal request and allow the building to exist with two independent Occupancy Categories.