Nashua, New Hampshire
Nashua, NH Accessory Dwelling Unit (ADU) Rules
City Acceptance Rating: 5/10
Last Updated: 8.28.2024
Image Source: City of Nashua
What You Need To Know
An ADU must be clearly secondary to the main home, limited to 750 square feet, and only one ADU is allowed per lot. The ADU's design must match the primary home's architectural style, and no new entrances can face the street. The owner must live in either the main dwelling or the ADU.
Type of ADU Permit Required
If all requirements are met only standard building permits are needed.
ADU Rules
The accessory dwelling unit (ADU) must be clearly secondary to the primary structure and cannot exceed 750 square feet.
Only one ADU is allowed per lot with a single-family home.
The ADU must not change the single-family character of the home or its neighborhood appearance:
No new entrances or exits for the ADU on the front or street-facing side of the home.
No new curb cuts from the street.
The ADU's exterior design must match the home's architectural style, scale, and materials.
The property owner must live in either the primary dwelling or the ADU as their principal residence.
The property owner must file a covenant with the City of Nashua and the Hillsborough County registry of deeds, stating the property contains an ADU and must comply with all applicable ordinances.
One additional off-street parking space is required beyond the standard for a single-family home.
An interior door must connect the primary dwelling and the ADU.
The primary home and the ADU must remain under the same ownership and cannot be separately sold or converted to condominiums.
ADUs are only allowed with single-family detached homes and are not permitted with manufactured housing.