The open space, lot coverage and yard modifications of this Section shall apply as follows.

(a)        Permitted obstructions

(1)        Easement volumes in all zoning districts

Any portion of an easement volume shall be considered a permitted obstruction within a required open space, yards, rear yard equivalent, or court pursuant to the regulations of this Resolution. Any easement volume, including any use or structure therein, shall be located at least 30 feet from any legally required window at the same level on the zoning lot.

(2)        Non-residential uses in Commercial or Manufacturing Districts

Any building or portion of a building used for any permitted commercial or community facility uses, up to two stories, excluding basements, or 30 feet above curb level, whichever is less, shall be considered a permitted obstruction in any rear yard or rear yard equivalent of a zoning lot with an easement volume serving an above-grade mass transit station. Any portion of a building containing residences or rooms used for living or sleeping purposes (other than a room in a hospital used for the care or treatment of patients, or joint living-work quarters for artists) shall not be a permitted obstruction.

(b)        Special open space modifications in certain districts

In R5D Districts and Commercial Districts mapped within or with a residential equivalent of an R5 or R5D Districts, the provisions of paragraph (g) of Section 23-142 (Open space and floor area regulations in R1 and R2 Districts with a letter suffix and R3 through R5 Districts) shall not apply.

(c)        Special lot coverage modifications in certain districts

The underlying lot coverage provisions shall apply except as modified pursuant to this paragraph.

(1)        Any easement volume, or portion thereof, that is open to the sky shall not be included in lot coverage.

(2)        In R5D Districts and Commercial Districts mapped within or with a residential equivalent of an R5 or R5D Districts, the maximum residential lot coverage for interior lots or through lots shall be 65 percent, and the maximum residential lot coverage for corner lots shall be 85 percent. Such provisions shall also apply to buildings utilizing the optional provisions for a predominantly built-up area.

(3)        In R6 and R7 Districts, for Quality Housing buildings, the maximum residential lot coverage for interior lots and through lots shall be 70 percent.