The vested rights doctrine allows a property developer to proceed with a project under the rules and regulations in place at the time that its rights vested, despite subsequent changes to the law. The concept derives from common law and is an equitable doctrine. In Ocean Bay Mart v. The City of Rehoboth Beach, Delaware, C.A. No. 2019-0467-SG (Del. Ch. Oct. 13, 2021), Vice Chancellor Sam Glasscock traced the evolution of the vested rights doctrine in Delaware and sought to clarify its application despite a “tangled” history.

For several years, Ocean Bay Mart, Inc., sought to develop property in the city of Rehoboth Beach into a condominium consisting of multiple single-family detached and attached units. The property consisted of a single lot that had been zoned C-1, which permitted single family detached homes provided no more than one main building could be erected on a single lot.