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.

Variances are typically only granted after undergoing a statutory review process against specified approval criteria. Although review criteria vary from jurisdiction to jurisdiction, three basic criteria are common the vast majority of variance ordinances:

• The variance is required due to specific site conditions (topography, soil conditions, etc.),
• Granting the variance will not result in a hazard to public health or safety, and,
• Granting the variance will not result in a grant of special privilege to the property owner (in other words, any other property owner with similar site conditions could obtain a similar variance: this criteria is often addressed by citing precedent)

Urban studies and planning | Local government in the United States