What is a "variance" in the zoning context?  Simply, it is relief from  -- or a variation of -- the application of a zoning law to a particular piece of property. 

Let's look a little harder at the process in North Carolina, which is quasi-judicial and nuanced.

When and landowner can show a local board (most often a board of adjustment, which is specified in State law, but sometimes a planning board or even a governing board) through a quasi-judicial proceeding that "unnecessary hardships" -- and only "unnecessary hardships" -- will result "from carrying out the strict letter of a zoning ordinance," then the presiding board "shall vary any of the provisions of the [zoning] ordinance upon a showing of all of the following":

1. Unnecessary hardship would result from the strict application of the ordinance. It shall not be necessary to demonstrate that, in the absence of the variance, no reasonable use can be made of the property.
2. The hardship results from conditions that are peculiar to the property, such as location, size, or topography. Hardships resulting from personal circumstances, as well as hardships resulting from conditions that are common to the neighborhood or the general public, may not be the basis for granting a variance.
3. The hardship did not result from actions taken by the applicant or the property owner. The act of purchasing property with knowledge that circumstances exist that may justify the granting of a variance shall not be regarded as a self-created hardship.
4. The requested variance is consistent with the spirit, purpose, and intent of the ordinance, such that public safety is secured, and substantial justice is achieved.

N.C.G.S. 160A-388(d).

Not only must the applicant for the variance show each and all of the foregoing, but the quasi-judicial board must vote as follows to grant a variance: "The concurring vote of four-fifths of the board shall be necessary to grant a variance."  N.C.G.S. 160A-388(e)(1). 

It is not uncommon for zoning ordinances to provide more detailed standards building upon these State law requirements.  However the State law standards above are mandatory; local governments may provide additional guidance and elaboration of these State law standards by way of their local zoning ordinances, but local governments are preempted from adopting standards that contradict or even depart from these State law standards.

Upon granting the variance, the local government may impose conditions on the variance provided the conditions are reasonably related to the condition or circumstance that gave rise to the need for the variance.  Indeed, local zoning ordinances will often direct the deciding quasi-judicial board to impose conditions on variances.  If a variance applicant accepts and acts on the variance imposed with conditions, the conditions are binding and cannot be challenged; that is, the applicant is "estopped".    If an amendment to variance conditions is sought, the amendment effort must proceed through the entire variance procedure; in essence, a new variance is being sought.

Variances (and conditions) apply to and run with the property.  Therefore, the transfer of ownership or occupancy has no impact on the application of a variance or its conditions. 

Lastly, and in some ways most commonly asked in cocktail parties, a variance is not allowed for a use.  N.C.G.S. 160A-381(b1).  That is, if a use is not permitted in a zoning district, State law expressly prohibits a variance to permit that use.  In that case, the applicant needs either a new use or an amendment to the zoning laws.

Lastly, lastly, in 2013, the North Carolina General Assembly amended State law to allow for variances in other "ordinance[s] that regulate[] land use or development", as well.  S.L. 2013-126 (sec. 1); N.C.G.S. 160A-388(d).  However, before we get excited, the local ordinances must expressly provide for variances in those other "non-zoning' laws that "regulate[] land use or development" (think, for example, subdivision laws); unlike variances from zoning laws, which are allowed under State law regardless of local ordinance provision.