Accessory Dwelling Units

Accessory Dwelling Units (ADUs) are additional living spaces located on a single residential lot. These can be located within or attached to the primary structure or incorporated into a detached structure such as a garage, barn, or other accessory building.

Dover allows ADUs in all residential districts where one dwelling unit currently exists (Dover Code 170- 24). There are several regulations that apply to Dover’s ADUs:

• An ADU is not permitted where there is already more than one dwelling unit on a property.
• A second ADU unit is permitted in residential districts other than R-40 if the second unit meets HUD Fair Market Rent rates for Dover.
• The resulting structure must look like a single-family home.
• The ADU may be attached or detached and must be at least 350 square feet and no greater than 950 square feet.
• The ADU must have one dedicated off-street parking space.
• The units may not be converted to a condominium or any other form of ownership other than a single-family dwelling. This must be recorded with Strafford County Registry of Deeds as a restrictive covenant in favor of the City.
• The property owner must occupy one of the two dwellings, main house or ADU.
• The dwelling units may have separate electric meters.
• Requires an annual, no-cost permit of use to be filed with the city.

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