Variance (land use)
In zoning, a variance is an administrative exception to land use regulations, generally in order to compensate for a deficiency in a real property which would prevent the property from complying with the zoning regulation. Variances are required in the United States in order to prevent a regulatory taking.
An example: suppose a "low density residential" zone requires that a house have a setback (the distance from the edge of the property to the edge of the building) of no less than 100 feet (30 m). If a particular property were only 100 feet (30 m) deep, it would be impossible to build a house on the property, potentially resulting in an unlawful regulatory taking. A variance exempting the property from the setback regulation would allow a house to be built.