Nonconforming use in

urban planning Urban planning, also known as town planning, city planning, regional planning, or rural planning, is a technical and political process that is focused on the development and design of land use and the built environment, including air, water ...

is a type of

zoning Zoning is a method of urban planning in which a municipality or other tier of government divides land into areas called zones, each of which has a set of regulations for new development that differs from other zones. Zones may be defined for a s ...

variance In probability theory and statistics, variance is the expectation of the squared deviation of a random variable from its population mean or sample mean. Variance is a measure of dispersion, meaning it is a measure of how far a set of number ...

where a parcel of land may be given an exception from current zoning ordinances due to improvements made by a prior owner or before the current zoning ordinances made the desired use non-conforming under local law.

Secondary suite Secondary suites (also known as accessory dwelling units, ADUs, in-law apartments and granny flats) are self-contained apartments, cottages, or small residential units, that are located on a property that has a separate main, single-family home, ...

s are commonly permitted as a non-conforming use in the zoning district they are located in because the suite was developed prior to the zoning ordinance coming into effect.

Discontinuance

Intent

The landowner may explicitly intend to discontinue the use by agreeing to end the use. Implied intent exists if the landowner fails to exercise the nonconforming use. If the landowner discontinues the nonconforming use after a specified period, commonly 21 years in many jurisdictions but shorter in many others, then the nonconforming use will be terminated and parcel will become subject to the zoning requirements of the area in which it is located. Such a discontinuance of the use implies the intent to abandon the use.

Partial destruction

In some jurisdictions, if the structure exercising the nonconforming use is destroyed beyond a certain percentage (usually 50%) it cannot be rebuilt or repaired. Instead, the parcel becomes subject to the applicable zoning regulations thereby ending the nonconforming use's reprieve from the zoning regulations. In others, by statute usually allowed to rebuild within a limited period. If dwelling, usually permitted to rebuild.

Replacement of non-conforming mobile homes

Local governments may, and often do, prohibit the replacement of older non-conforming mobile homes with newer non-conforming mobile homes because the replacement tends to perpetuate and extend the time the non-conforming use continues. See e.g. Lincoln County North Carolina. Code §10.2.3; Linn County, Iowa Code Art. 3, sec.1 para.6; Davenport Florida City Code §5.01.04.

Amortization

Some states allow amortization of the nonconforming use whereby the nonconforming use's immediate value is amortized over the course of a set period and onc