The lawful use of a structure, land, or water, existing at the time of adoption of or amendment to this chapter, may be continued although the use does not conform to the provisions of this chapter; however:
A. 
Only that portion of the land, structure, or water in actual use may be continued. The use may not be extended, enlarged or substituted except as required by law or order so as to comply with the provisions of this chapter.
B. 
Substitution of new equipment may be permitted by the Board of Adjustment if such equipment will reduce the incompatibility of the nonconforming use.
C. 
If the nonconforming use is discontinued or terminated for a period of 12 months, any future use of the structure, land or water shall conform to the provisions of this chapter.
A structure, existing at the time of adoption of or amendment to this chapter, may be continued although its size or location does not conform to yard, height, parking, loading, or access provisions of this chapter; however:
A. 
It shall not be extended, enlarged, reconstructed, moved or structurally altered except when allowed or required by law or order to comply with the provisions of this chapter.
B. 
A nonconforming structure damaged by fire, explosion, flood, the public enemy, or other calamity to the extent of 50% or more of its equalized value shall not be restored except to comply with the provisions of this chapter. Pursuant to § 59.69(10m), Wis. Stats., and notwithstanding any other provision of this chapter, a nonconforming structure damaged or destroyed by violent wind, vandalism, fire, flood, ice, snow, mold or infestation after March 2, 2006, may be restored to the size, location, and use that it had immediately before the damage or destruction occurred, and no limits may be imposed on the costs of the repair, reconstruction, or improvement of said structure. The size of the restored structure may be larger than the size it was immediately before the damage or destruction if necessary for the structure to comply with applicable state or federal requirements.
C. 
Residential structures which encroach upon required yards may be structurally altered, provided they will not create a greater degree of encroachment.
A. 
A dwelling built on an existing nonconforming lot in a certified Farmland Preservation District must be either a farm residence, a conditional use that qualifies under § 91.46(2)(c), Wis. Stats., or rezoned out of the district.
B. 
In any residential district, a single-family detached dwelling and its accessory structures may be erected on any legal lot of record in the Adams County Register of Deeds office, provided that requirements of all other applicable ordinances are met. Such lot or parcel shall be in separate ownership from abutting lands. If in separate ownership, all the district requirements shall be complied with insofar as practical but shall not be less than the following:
(1) 
Lot width: 50 feet minimum.
(2) 
Lot area: 10,000 square feet minimum.
C. 
In an A-3 Secondary Agricultural District, structures may be erected on a legal lot of record in the Adams County Register of Deeds office before the effective date or amendment of this chapter, provided that requirements of all other applicable ordinances are met. Such lot or parcel shall be in separate ownership from abutting lands. If in separate ownership, all the district requirements shall be complied with insofar as practical but shall not be less than the following:
(1) 
Lot width: 150 feet.
(2) 
Lot area: five acres.
D. 
If abutting lands and the substandard lot are in the same ownership, the substandard lot shall not be sold or used without full compliance with the provisions of this chapter.
Once a nonconforming use, lot, or structure has been changed to conform, it shall not revert to a nonconforming use, lot, or structure. Once the Board of Adjustment has permitted the substitution of a more restrictive nonconforming use for an existing nonconforming use, the previous use shall lose its status as a legal nonconforming use.