A nonconforming front yard setback line in the Low-Density Residential District which has been duly recorded may be used without obtaining a variance.

A single-family dwelling may be built upon a lot (either recorded or not recorded) using the average of nonconforming front yard setbacks of existing dwellings on all lots in the same block on the same side of the street without a variance.

Where at the time of passage of this chapter or amendment thereto, lawful use of land or buildings exists which could not be permitted by the regulations imposed by this chapter, including parking requirements, the specific use may be continued, provided that the use is not abandoned.

At the effective date of the enactment or amendment of this chapter, a lawful use of a lot or structure exists that is made no longer permissible under the terms of this chapter as enacted or amended, such use may be sold or otherwise transferred to other owners and may be continued as long as it remains otherwise lawful in accordance with the provisions of this chapter.

When a nonconforming use of a structure and/or lot is discontinued or abandoned for six consecutive months, the structure and/or lot shall not thereafter be used, except in conformance with the regulations of the zoning district in which it is located, except that when the discontinuance was beyond the control of the owner or tenant and was without intent to abandon the use, the Zoning Hearing Board may, when application is made not later than one year from the date the use was discontinued, approve an extension of not more than one additional year within which the use may be resumed. Additional extensions may be approved at the Zoning Hearing Board's discretion.

From the time of such application to reinstitute or continue the use, the landowner and/or developer shall have not more than one year to complete the structure or reinstitute the use.

A nonconforming use may be expanded by 25% of the space occupied at the effective date of this chapter with the approval of a special exception by the Zoning Hearing Board, and subject to the criteria established for special exceptions under this chapter, provided that the expansion is shown not to be detrimental to the public health and safety, and further provided that the nonconforming use has not previously been expanded by as much as 25% within 10 years prior to the effective date of this chapter. However, the use may not be expanded to a lot not owned at the effective date of this chapter and may not create any new nonconformities as to structures or lot requirements.

Where a structure principally devoted to a nonconforming use is destroyed by casualty to the extent of 75% of the cost of construction at the time of destruction of the bulk of its improvements or becomes so dangerous or dilapidated that substantially complete reconstruction is necessary, reconstruction for continuation of the nonconforming use shall be denied.

No new nonconforming uses can be added to the premises. Only the specific principal use in existence at the effective date of this chapter has protected status.

A nonconforming accessory use cannot become the basis for a nonconforming principal use.

If no structural alterations are made, any nonconforming use of a structure may as a special exception be changed to another nonconforming use, provided that the Zoning Hearing Board shall find that the proposed use is equally appropriate or more appropriate to the district than the existing nonconforming use. In permitting such change, the Zoning Hearing Board shall require appropriate conditions and safeguards in accordance with Parts 4 and 11. No such nonconforming use granted by the Zoning Hearing Board shall be considered a use by right.

Any building which is nonconforming as to lot coverage or is deficient in parking may not be enlarged.

A single-family dwelling which has side yards less than that required may be expanded to the rear or front, provided that such expansion results in no further decrease in the side yards and the expansion will comply with the rear or front yard and percentage of lot coverage requirements of the district.

A single-family dwelling which has a front or rear yard less than that required may be expanded to the side, provided that such expansion results in no further decrease in the front or rear yards and the expansion complies with the applicable side yard and percentage of lot coverage requirements of the district.

A single-family dwelling which has side, front or rear yards less than that required may be expanded vertically, provided that such expansion will comply with applicable height requirements.

All buildings other than single-family dwellings which are nonconforming by setbacks, height, etc., may be enlarged if a variance is granted by the Zoning Hearing Board, provided that the nonconformity is not increased and no new nonconformities are created (unless a variance is granted), including lot and parking requirements, and provided that the criteria in § 440-903 are met.

Should a nonconforming building or nonconforming portion of a building be destroyed by casualty or become so dangerous or dilapidated that replacement would represent 75% of the cost of construction at the time of destruction, it shall not be reconstructed except in conformity with the provisions of this chapter.

Should a nonconforming building be moved for any reason for any distance whatever, it shall thereafter conform to the regulations for the district in which it is located after it is moved.

No other nonconforming structure shall be moved or enlarged unless it is brought into conformance with the requirements of this chapter.

Nonconforming signs and signs for nonconforming uses are regulated in Part 7.