Street improvements otherwise required by this subchapter shall not be required as follows.
(A) Street improvements shall not be required where the construction, alteration or addition consists solely of installation or replacement of mechanical equipment.
(B) Street improvements shall not be required where additions or alterations to a building do not increase the floor area of the building by more than 25% of the original building before the addition or alteration is started. Whenever the subtotal of all alterations and additions exceeds 25% of the determined original floor area, street improvements shall be required. Each and every addition or alteration shall be added to the other to determine the applicable percentage.
(1990 Code, § 7-6-7)