Permitted obstructions in required yards, courts, and open spaces for all zoning lots

The regulations for permitted obstructions in yards, courts and open space shall be modified in accordance with the provisions of this Section.

(a)        Mechanical equipment

In all districts, the underlying allowances for accessory power systems as permitted obstructions in any open space, yard, rear yard equivalent, or court, may be expanded to include all accessory mechanical equipment, provided that:

(1)        all equipment shall be subject to the following enclosure and screening requirements, as applicable:

(i)        all power system equipment shall be enclosed within a building or other structure, or screened, as applicable, pursuant to the requirements set forth in the applicable underlying district allowances;

(ii)        all other types of equipment, including all mechanical, electrical and plumbing equipment, shall be completely enclosed within a building or other structure, except as necessary for mechanical ventilation; and

(2)        the size and location of all accessory mechanical equipment, including all screening and enclosures containing such equipment, shall not exceed the size limitations specified in the underlying allowances, except that, where such equipment is elevated above the flood-resistant construction elevation, the permitted size and location of such accessory mechanical equipment may be modified as follows:

(i)        where any equipment is required to be located at least five feet from any lot line, such distance may be reduced to three feet for zoning lots that have less than the prescribed minimum lot area or lot width required by the applicable district regulations;

(ii)        the maximum height of such permitted obstructions for the applicable district:

(a)        may be measured from the reference plane instead of the level of the adjoining grade or curb level, as applicable; or

(b)        for zoning lots containing residences and a lot area greater than or equal to one and one-half acres, may exceed the applicable height limitations, provided that:

(1)        such equipment is contained within a building or other structure that is located at least 30 feet from any legally required window;

(2)        any stack associated with heating, ventilation, and air conditioning (HVAC) systems exhausts at a height at least as tall as the tallest building containing residences on the zoning lot; and

(3)        such building or other structure complies with one point of the streetscape mitigations set forth in Section 64-52 (Ground floor level mitigation options); and

(iii)        the maximum area that such equipment may occupy within a required side yard, rear yard or rear yard equivalent, or any court containing legally required windows need not apply where the height of such obstructions do not exceed the applicable underlying height allowances, as modified by the provisions of paragraph (a)(2)(ii)(a) of this Section.

(b)        Berms

In all districts, structural landscaped berms and associated flood gates, including emergency egress systems that are assembled prior to a storm and removed thereafter, shall be permitted obstructions in any required open space, yard or rear yard equivalent on the zoning lot, provided that the height of such berm does not exceed the highest flood-resistant construction elevation required on the zoning lot, or five feet above the lowest adjoining grade, whichever is higher.

(c)        Flood control devices

In all districts, temporary flood control devices and associated permanent fixtures, including emergency egress systems that are assembled prior to a storm and removed thereafter shall be permitted obstructions in yards and rear yard equivalents, courts, open space, public plazas, arcades, pedestrian circulation spaces and all other publicly accessible open spaces. However, permanent fixtures for self-standing flood control devices installed in publicly accessible open areas, arcades, and pedestrian circulation spaces shall be flush-to-grade.

(d)        Steps

In all Residence Districts, the provisions of paragraph (a)(17) of Section 23-44 (Permitted Obstructions in Required Yards or Rear Yard Equivalents) shall be modified to allow steps within a required yard or rear yard equivalent, provided that such steps access any story located at or below the first story above the flood elevation.