The regulations of this Section governing certain structural and operational requirements shall apply to all enclosed sidewalk cafes.

(a)        Ceiling

The ceiling of an enclosed sidewalk cafe shall be of incombustible materials, including colored or colorless safety glass or fabric which has been treated to be fire resistant as approved by the Department of Buildings.

At no point shall the height of the ceiling of an enclosed sidewalk cafe be lower than 7 feet, 0 inches above the floor of the sidewalk cafe.

(b)        Transparency — exterior walls

An enclosed sidewalk cafe may provide a base wall of opaque material up to a maximum height of 12 inches from the finished floor level. The base wall shall include any horizontal structural members that support transparent materials above.

All enclosing walls, doors and windows, except for the structural members, above finished floor level or base wall as provided in this Section, up to a height of 7 feet, 0 inches above finished floor level, must be of colorless, untinted, non-reflective, transparent material, as approved by the Department of Buildings. In order to maximize transparency, the horizontal as well as vertical structural members shall not be sized more than 10 inches wide.

At least 50 percent of the walls, up to a height of 7 feet, 0 inches above finished floor level, shall consist of operable transparent windows.

(c)        Elevation

The enclosed sidewalk cafe floor shall not be more than seven inches above the level of the adjoining sidewalk.

In the event of a major grade change, however, the City Planning Commission may, by certification, permit the floor level to be more than seven inches above the level of the adjoining sidewalk.

(d)        Designated boundaries

No portion of enclosed sidewalk cafes, such as doors, windows, walls or any objects placed within an enclosed sidewalk cafe, shall swing or project beyond the designated exterior perimeter of the enclosed sidewalk cafe. However, fire exit doors that are used exclusively as emergency fire exit doors shall be exempt from this provision.

(e)        Fixtures

The furnishings of the interior of an enclosed sidewalk cafe shall consist solely of moveable tables, chairs and decorative accessories. No objects, except lighting fixtures and HVAC installations, may be permanently affixed onto any portion of the wall of the enclosed sidewalk cafe. In no event shall such objects penetrate the exterior perimeter of the wall or the roof of the enclosed sidewalk cafe or impede the transparency as required by this Chapter. The exhaust for such HVAC installations on the adjacent walls shall not be less than 10 feet above curb level.

(f)        Refuse storage area

No structure or enclosure to accommodate the storage of garbage may be erected or placed adjacent to or separate from the enclosed sidewalk cafe on the public right-of-way.