The Village of Tarrytown accessory dwelling unit (ADU) regulation allows for one ADU per single-family lot (upon approval). The Building Department decides if an ADU is approved and only when there is a need for construction is site plan approval by the Planning Board or Architectural Review Board needed. There is a six-month minimum lease requirement for renting out an ADU. The ADU must be a minimum of 300 square feet and a maximum of 1,000 square feet or 50% of the total floor plan of the primary residence. Additionally, the regulation includes specifications on other design requirements, water and sewage, parking, and more.