Within the districts established by this chapter or amendments that may later be adopted there exist lots, structures, and uses of land and structures which were lawful before this chapter was passed or amended, but which would be prohibited under the terms of this chapter or future amendment.

It is the intent of this chapter to permit these nonconformities to continue until they are removed. Such uses are declared by this chapter to be incompatible with permitted uses in the districts involved. Nonconformities may be enlarged as decided by the Zoning Hearing Board.

A nonconforming use of a structure, a nonconforming use of land, or nonconforming use of a structure and land shall not be extended or enlarged after passage of this chapter by the addition of other uses if such additions are of a nature which would be prohibited generally in a district; or the attachment of additional signs or display devices on the land outside the building.

Nothing in this chapter shall be deemed to require a change in the plans, construction, or designated use of any building on which actual construction was lawfully begun prior to the effective date of adoption or amendment of this chapter and upon which actual building construction has been continuously carried on. "Actual construction" includes the placing of construction materials in permanent position and fastened in a permanent manner, and demolition, elimination, and removal of an existing structure in connection with such constructure, provided that actual construction work shall be continuously carried on until the completion of the building involved.

No such nonconforming use shall be expanded to occupy a greater area of land than was occupied at the effective date of this chapter, except as specified by § 280-21 of this chapter.

No such nonconforming use shall be moved to any other portion of the lot occupied by such use at the effective date of this chapter.

If any such nonconforming use of land ceases for any reason for a period of more than 12 months, any subsequent use of such land shall conform to the regulations for the district in which such land is located.

A structure may not be enlarged or altered unless a variance is granted by the Zoning Hearing Board.

Should such structure be destroyed by fire, flood, explosion or other casualty to an extent of more than 50% of its replacement cost at time of destruction, it shall not be reconstructed except in conformity with the provisions of this chapter unless a variance is granted by the Zoning Hearing Board. Replacement cost shall be determined by obtaining cost of reconstruction from the following sources: one building contractor selected by the owner and one building contractor selected by the Borough. The average cost of replacement will then be ascertained after receipt of both costs.

Should such structure be moved for any reason, it shall thereafter conform to the regulations for the district in which it is located after moved.

An existing structure devoted to a use not permitted in the district in which it is located may not be enlarged, extended, constructed, reconstructed, or structurally altered unless a variance is granted by the Zoning Hearing Board.

Any nonconforming use may be extended throughout any parts of a building, but no such use shall be extended to occupy any land outside such building.

If no structural alterations are made, any nonconforming use of a structure, or structure and premises, may be changed to another nonconforming use provided that the Zoning Officer shall find that the proposed use is equally or more appropriate to the district than the existing nonconforming use. Applications for changes to nonconforming uses, structures or lots which are equal or less nonconforming may follow normal permit procedures under the Zoning Officer.

Once a nonconforming use is superseded by a permitted use, the nonconforming use shall not be resumed.

When a nonconforming use of a structure, or structure and premises in combination, is discontinued or abandoned for 12 consecutive months, it shall not be used except in conformance with the regulations of the district in which it is located.

When nonconforming use status applies to a structure and premises in combination, removal or destruction by owner of the structure shall eliminate the nonconforming status of the land, unless the structure is rebuilt within 12 months.

On any building devoted in whole or in part to any nonconforming use, work may be done on ordinary repairs, or on repair or replacement of nonbearing walls, fixtures, wiring, or plumbing, without the requirement of a permit.

Nothing in this chapter shall be deemed to prevent the strengthening or restoring to a safe condition of any building or part thereof declared to be unsafe by any official charged with protecting the public safety, upon order of such official.