R.I. Gen. Laws § 1-3-15: Variances.

Any person desiring to erect any structures; increase the height of any structure; permit the growth of any tree; or otherwise use his or her property in violation of airport zoning regulations adopted under this chapter may apply to the board of appeals, as provided in §§ 1-3-18 — 1-3-26, for a variance from the zoning regulations in question. Variances shall be allowed where a literal application or enforcement of the regulations would result in practical difficulty or unnecessary hardship and the relief granted would not be contrary to the public interest but do substantial justice and be in accordance with the spirit of the regulations of this chapter.