The City Planning Commission may authorize a horizontal enlargement, or a development consisting of no more than one building containing a non-accessory use, on one or more zoning lots, and may modify the bulk regulations of the underlying district, except floor area ratio regulations, provided that:

(a)        the site plan, to the extent practicable, minimizes the need for new paving and impervious surfaces upon the zoning lot;

(b)        the site plan provides access to the new or enlarged building using streets that were improved and open to traffic on the date of application for an authorization, and which serve other occupied buildings;

(c)        the site plan, to the extent practicable, minimizes adverse effects on wetlands, planned open space, drainage, or other functions in the surrounding area;

(d)        the resulting building and other site improvements would not impair the essential ecological character of the surrounding area for its future use as open space;

(e)        the site plan and resulting building incorporate such measures as are reasonable to minimize risks to public safety from natural hazards such as flooding and wildfires; and

(f)        where the Commission is modifying bulk regulations, such modifications are the minimum necessary to protect, or provide buffering from, wetlands or wetland-adjacent areas.

The Commission may prescribe additional conditions and safeguards to minimize adverse effects on the character of the surrounding area.