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.
Resources:
Berlin, New Hampshire
Berlin, NH Accessory Dwelling Unit (ADU) Rules
City Acceptance Rating: 5/10
Last Updated: 8.28.2024
Image Source: NH PBS
What You Need To Know
To increase housing options while preserving neighborhood aesthetics, attached ADUs are permitted by the Planning Board through a Conditional Use Permit
Type of ADU Permit Required
Attached ADUs are permitted by the Planning Board through a Conditional Use Permit.
ADU Rules
One ADU Per Property: Only one ADU is allowed per property, and it is not permitted on properties with more than one primary dwelling unit (PDU).
Location: The ADU must be within or added to an existing or proposed single-family dwelling.
Self-Sufficient Living Quarters: The ADU must have its own sleeping, bathing, and eating facilities.
Exterior Changes: Exterior alterations to the PDU are allowed to accommodate the ADU but must not make the PDU look like a duplex or multifamily structure. Access ways should be placed at the side or rear of the building. The ADU should remain functionally dependent on the PDU, with no separate utilities, garages, or driveways. The ADU may have up to two bedrooms.
Size: The ADU must be no larger than 1,000 square feet and must not exceed 40% of the living area of the PDU.
Internal Connection: The ADU must be internally connected to the PDU.
Owner Occupancy: The property owner must live in one of the two units.
Parking: One additional parking space for the ADU must be provided if space is available on the property.
No Separate Ownership: The PDU, ADU, and lot cannot be converted to separate legal ownership. A restrictive covenant must be recorded in the Coos County Registry of Deeds, with copies provided to the Community Development Department and the Assessor before a Certificate of Occupancy is issued.
Septic Requirements: If municipal sewer service is unavailable, the septic system must meet NH Water Supply and Pollution Control Division standards for the combined occupancy of the property.
Resources:
https://www.berlinnh.gov/sites/g/files/vyhlif2811/f/uploads/chapter_17_zoning_ordinance_4-17-23_0.pdf#:~:text=A%20maximum%20of%20one%20(1,3.