15-0629 v3.X Walk-off System Requirements for Urban Existing Building
Question:
We are requesting a number of walk-off systems execptions for our tenant fit out petal certification project. The project is located in an existing building in an urban environment, with little ability to impact the exterior envelope and entry way systems resulting from city and landlord restrictions. We currently have two main entrances, a retail store entrance, and multiple roof terrace entrances, and would like to request exceptions for the following alternative approaches: For the public/private main entrance (see attached image) we a proposing chopping the exterior concrete pavers and installing an exterior 8' foot grille, in combination with a grille inside the revolving door vestibule to act as our vestibule “finishing system”. For the ADA door to one side of the revolving doors we are proposing a temporary internal walk off mat, as an alternative to a vestibule, resulting from spatial constraints associated with the existing conditions of the building. The retail store entrance located adjacent to the main entrance runs right up against a pedestrian sidewalk. Becuase of the small size of the store, we cannot install a vestibule on the interior of the space without losing a signifigant area of valuable retail floor space. We are proposing a 4' temporary walk off mat on the interior of the space in lieu of a vestible. The concrete sidewalk would serve as the exterior walk off system. For the secondary entrance the door runs right up against a pedestrian sidewalk (see attached image; note the condition shown in the image will be demo'd and is properly represented in the attached sketch). We are not permitted by the city or landlord to place a grille or temporary walk-off mat on the sidewalk, so instead we are proposing to place a mat for entire floor in the vestibule entryway (as shown in the attached sketch). The concrete sidewalk would serve as the exterior walk off system. At each entryway from the terrace (see attached sketch for typical entrance) we are proposing a integrated walk-off grille on the interior ramp at minimum distance of 3' in length. There is no vestibule due to space constraints and the exterior pavers would serve as the exterior walk-off system.
Answer:
The Institute recognized the constraints on existing buildings and is therefore creating a new Exception (below) and will accept the following:
1. The proposed system meets requirements if there is a 4' overhang and signage requesting use of the revolving door (so the ADA door is secondary).
2. An existing building with an zero lot line entry may have all of the required walk off mat within the interior based on the new exception below. Due to the space constraints of the retail store, the proposed 4' walk off mat is acceptable in this case, but it must be cleaned at least once a week, and possibly more depending on traffic and weather. Vestibules are not required in existing buildings where it is not feasible.
3. This strategy is acceptable given the spatial constraints of the existing sidewalk and structural wall at the stair.
4. The terrace pavers along with the proposed 3' interior mat is acceptable off a private terrace. Existing buildings where it is not feasible to alter the interior or exterior floor area may comply through the following new exception
(v2.1) I08-E3 Existing Building Entrances (v3.0) I08-E3 Existing Building Entrances
Existing building projects may provide temporary dirt walk-off systems if a permanent dirt walk-off system and/or vestibule is infeasible due to the configuration of the existing space or jurisdiction restrictions. The temporary dirt walk-off system must be at least 8 ft and maintained at least on a weekly basis.
Documentation:
I08-a Exception Narrative - The narrative must make the case that altering the building with a permanent entry approach (in-floor or vestibule) is either prohibited by the AHJ (include supporting documents) or is infeasible.
I08-c Photographs - Photographs should be taken before construction to support a case that the installation of permanent dirt walk-off systems is infeasible.
Post ID 3013