A.   Any lawfully established use of a building or land, on the effective date of this Title or of amendments thereto, that does not conform to the use regulations for the district in which it is located, shall be deemed to be a legal nonconforming use and may be continued, except as otherwise provided herein.

   B.   Any legal nonconforming building or structure may be continued in use provided there is no physical change other than necessary maintenance and repair, except as otherwise permitted herein.

   C.   Any building for which a permit has been lawfully granted prior to the effective date of this Title or of amendments thereto, may be completed in accordance with the approved plans; provided construction is started within ninety (90) days and diligently prosecuted to completion. Such building shall hereafter be deemed a lawfully established building.

   A.   Whenever any part of a building, structure or land occupied by a nonconforming use is changed to or replaced by a use conforming to the provisions of this Title, such premises shall not thereafter be used or occupied by a nonconforming use, even though the building may have been originally designed and constructed for the prior nonconforming use.

   B.   Whenever a nonconforming use of a building or structure or part thereof has been discontinued for a period of twelve (12) consecutive months, or whenever there is evident a clear intent on the part of the owner to abandon a nonconforming use, such use shall not, after being discontinued or abandoned, be re- established, and the use of the premises thereafter shall be in conformity with the regulations of the district in which it is located.

   C.   Where no enclosed building is involved, discontinuance of a nonconforming use for a period of six (6) months shall constitute abandonment, and shall not thereafter be used in a nonconforming manner.

The nonconforming use of any building, structure or portion thereof, which is designed or intended for a use not permitted in the district in which it is located, may be changed to another nonconforming use thereof but only if such other use is permitted by a special use permit as authorized in Chapter 12 of this Title.

   A.   Exemptions:

      1.   No building, structure or use rendered nonconforming by virtue of this Title shall be subject to the amortization provisions of this Section solely by reasons of being nonconforming with respect to the standards prescribed in this Title for any of the following:

   Building height

   Floor area ratio

   Yards--front, side or rear

   Lot area

   Lot width

   Gross floor area

   Off-street parking or loading spaces

      2.   No lawful building, structure or use located in any manufacturing district shall be subject to the amortization provisions of this Section, and lawful building, structure or use, located in a business district, shall be subject to the amortization provisions of this Title if it is a permitted building, structure or use in any business district.

      3.   A lawful building, structure or use shall be deemed to include any building, structure or use for which a building permit or occupancy permit has been issued prior to the effective date of this Title, and on which construction covered by such building permit is completed or will be completed within the required period of time, as set forth in this Title.

   B.   Amortization Schedules: All nonconforming rooming, boarding or lodging houses and nonconforming business and manufacturing buildings located in a residence district, and any building or structure which is located in a B-1 retail business district and all or substantially all of such buildings or structures designed or intended for a use permitted only in a B-2 limited service business or an M-1 or M-2 manufacturing district, shall be removed or shall be altered, remodeled or converted for a permitted use within six (6) months after the amortization period of such building or structure, which is hereby established in accordance with the respective amortization periods set forth below. Assessed valuations referred to in subsections B1, B2 and B3 of this section are the unequalized assessed valuations of improvements of a lot, established for real estate tax purposes for the year 1975 by Cook County:

      1.   Assessed valuation more than five thousand dollars ($5,000.00):

         a.   Fireproof construction and noncombustible construction: Forty (40) years from date of original building permit or twenty five (25) years from effective date of ordinance 66-15, whichever last occurs.

         b.   Exterior masonry wall construction: Thirty (30) years from the date of original building permit or twenty (20) years from effective date of ordinance 66-15, whichever last occurs.

         c.   Frame construction: Twenty (20) years from date of original building permit or ten (10) years from effective date of ordinance 66-15, whichever last occurs.

      2.   Assessed valuation at least two thousand dollars ($2,000.00) but not more than five thousand dollars ($5,000.00): Eight (8) years from date of original building permit or four (4) years from effective date of ordinance 66-15, whichever last occurs.

      3.   Assessed valuation under two thousand dollars ($2,000.00): Four (4) years from date of original building permit or two (2) years from effective date of ordinance 66-15, whichever last occurs. (Ord. 80-2-0, 12-1979)

   C.   Nonconforming Uses Of Land: The lawful use of any lot, parcel or tract of unimproved (vacant) land for storage or other purposes that does not conform to the provisions of this zoning code shall be discontinued upon the happening of any of the following events: improvement of the land with any permanent structure except fencing, or discontinuation of the use for a period of twelve (12) consecutive months, or whenever there is an evidently clear intent on the part of the owner to abandon such use. Such use shall not, after construction of such a permanent improvement, or discontinuation, or abandonment, be reestablished, and thereafter use of the lot, parcel or tract shall be in conformity with applicable regulations of this code. (Ord. 03-38-0, 11-12-2003)

   A.   Normal maintenance of a building or other structure containing a nonconforming use is permitted, including necessary nonstructural repairs and incidental alterations which do not extend or intensify the nonconforming use.

   B.   No structural alteration shall be made in a building or other structure containing a nonconforming use, except in the following situations:

      1.   When the alteration is required by law.

      2.   When the alteration will actually result in eliminating the nonconforming use.

      3.   When a building in a residential district containing residential nonconforming uses may be altered in any way to improve livability, provided no structural alteration shall be made which would increase the number of dwelling units or the bulk of the building. (Ord. 80-2-0, 12-1979)

If a building or other structure containing a nonconforming use is damaged or destroyed by any means to the extent of fifty percent (50%) or more of its replacement value at that time, the building or other structure can be rebuilt or used thereafter only for a conforming use and in compliance with the provisions of the district in which it is located. In the event the damage or destruction is less than fifty percent (50%) of its replacement value, based upon prevailing costs, the building may then be restored to its original condition and the occupancy or use of such building may be continued which existed at the time of such partial destruction.

In either event, restoration or repair of the building or other structure must be started within a period of six (6) months from the date of damage or destruction and diligently prosecuted to completion. (Ord. 80-2-0, 12-1979)

   A.   A nonconforming building may be enlarged or extended only if the entire building is thereafter devoted to a conforming use, and is made to conform to all the regulations of the district in which it is located.

   B.   No building partially occupied by a nonconforming use shall be altered in such a way as to permit the enlargement or expansion of the space occupied by such nonconforming use.

   C.   No nonconforming use may be enlarged or extended in such a way as to occupy any required usable open space, or any land beyond the boundaries of the zoning lot as it existed on the effective date hereof, or to display any conforming use in the same building or on the same parcel.

   D.   A building or structure which is nonconforming with respect to yards, floor area ratio, or any other element of bulk regulated herein shall not be altered or expanded in any manner which would increase the degree or extent of its nonconformity with respect to the bulk regulations for the district in which it is located. (Ord. 80-2-0, 12-1979)

Wherever a lawfully existing building or other structure otherwise conforms to the use regulations herein but is nonconforming only in the particular manner hereafter specified, the building and use thereof shall be exempt from the requirements of section 10-3-4 of this chapter:

   A.   In any residential district, where a dwelling is nonconforming only as to the number of dwelling units it contains, provided no such building shall be altered in any way so as to increase the number of dwelling units therein.

   B.   In any business district, where the required transitional yard is less than that specified in the regulations for the district in which it is located.

   C.   In any district where an established building, structure or use is nonconforming with respect to the standards prescribed herein for any of the following:

      1.   Gross floor area;

      2.   Yards - front, side, rear or transitional;

      3.   Off street parking or loading;

      4.   Building height. (Ord. 80-2-0, 12-1979)

   D.   In any lot that contained a legally constructed single-family residence at the time it became nonconforming solely because of insufficient dimensions and/or lot area shall be exempted from application of this chapter and shall remain buildable for single-family residence purposes, except if such use is abandoned for a period of six (6) consecutive months. (Ord. 98-42-0, 10-14-1998)

Any nonconforming use may be made a special use by the granting of a special use permit as authorized in chapter 12 of this title, provided said use is a permitted special use in the district in which it is located. (Ord. 80-2-0, 12-1979)