No such building which is nonconforming with respect to height, area or lot location or setback from any lot line shall be enlarged or altered in such manner as to increase any nonconformity, subject to the provisions of § 122-20 of this chapter.

No such building which is nonconforming with respect to use shall be enlarged or altered structurally except as may be allowed by law or this chapter.

No such nonconforming use shall be enlarged or extended nor shall it be changed to another nonconforming use.

No such nonconforming building or use, if changed to a building or use which conforms to the provisions of this chapter, shall thereafter be changed to a nonconforming use or building.

No such nonconforming use, other than tennis courts and swimming pools, if discontinued 12 consecutive months within a ten-year period, shall be resumed.

No such nonconforming building, if 50% or more of the assessed value of the structure is destroyed due to any cause, shall be restored in nonconforming form or location. However, if such nonconforming building is destroyed accidentally, it may, if so permitted by the Board of Zoning Appeals, be restored in substantially the same form and location, without substantial enlargement. However, tennis courts and swimming pools are exempt from this subsection.

If less than 50% of a nonconforming building is destroyed by natural causes, it may be restored only if a building permit is obtained and neither the restored portion of the building nor the nonconformity is included. However, tennis courts and swimming pools are exempt from this subsection.

The restoration referred to in Subsections F and G hereof must be commenced within one year and completed within two years of the destruction and, if not, the continuation of the nonconformity of the affected portion only shall cease.

If 25% or more of a nonconforming fence is destroyed, it must be rebuilt under the provisions of this chapter. This does not apply to ordinary repairs.

In the case of a lot on which there stands, on the effective date of this chapter, a dwelling or other principal building which conforms to the Building Zone Code in effect immediately prior to that date, which lot shall not at any time on or after the effective date hereof have been reduced in area or in any dimension, the fact that the area of such lot is less than that prescribed in Article IV of this chapter or that the width of the front lot line of said lot is less than that prescribed in Article IV of this chapter shall not prevent the erection, enlargement, alteration or maintenance on such lot of a building or buildings which, as so erected, enlarged or altered, do not increase any existing nonconformity with respect to setback or height and which comply with all the other provisions of this chapter.

An unimproved lot held in single and separate ownership prior to the effective date of this chapter and continuously thereafter which does not comply with the lot area and front line requirements of this chapter shall be exempt from the lot area and front line requirements of this chapter but shall comply with the area and front requirements, if any, of the Building Zone Law in effect at the time such lot was first held in single and separate ownership.

Building permit applications made prior to March 12, 1997, as modified and not denied prior to May 28, 1997, shall be granted, provided that the buildings for which building permits were so applied for conform to the restrictions of this chapter which were in force on March 12, 1997, and all other provisions of law.

No improved lot shall be reduced in area or in any dimension unless the lot so reduced has at least the area prescribed by Article IV of this chapter and has the unoccupied spaces required by the other provisions of this chapter.

No improved lot shall be reduced in length of the front lot line unless the lot as so reduced has at least the length of the front lot line prescribed in Article IV of this chapter.

No improved lot shall be reduced in area or in any dimension unless the setback of each then-existing building from any new boundary line shall be at least the setback which would be required by the other provisions of this chapter for a building of the same kind then newly erected in the same location.