Laconia, New Hampshire
Laconia, NH Accessory Dwelling Unit (ADU) Rules
City Acceptance Rating: 10/10
Last Updated: 8.28.2024
Image Source: City of Laconia
What You Need To Know
ADUs are allowed only on properties with an owner-occupied single-family home, with a limit of one ADU per lot. They do not affect density or lot size requirements, and the owner must live in either the main residence or the ADU.
Type of ADU Permit Required
Special exception permit, but changing to by-right soon. 8-24-24
ADU requirements are being rewritten to allow detached units.
A meeting next week will discuss updates from Planning Supervisor Rob Mona.
ADU Rules
Owner Occupancy: ADUs are permitted only on properties with an owner-occupied single-family dwelling, with a maximum of one ADU per lot.
Density and Lot Size: ADUs do not count as additional dwelling units for minimum lot size or density calculations.
Owner's Residence: The property owner must occupy either the main residence or the ADU as their primary residence. Temporary absences are allowed, but the owner-occupied unit cannot be rented out during the absence.
Location: ADUs must be in the same building as the main residence unless the lot meets or exceeds the minimum size for the zoning district. In such cases, the ADU can be in a separate structure (e.g., garage, barn) if it meets setback requirements.
Utilities and Living Quarters: ADUs must have self-sufficient living quarters (sleeping, bathing, eating). If in an addition to the main dwelling, the ADU must share utilities with the main residence. Detached ADUs may have separate municipal utility connections.
Water and Sewer: Where municipal services are unavailable, the ADU must comply with RSA 485-A:38 for water supply and sewage disposal.
Interior Connection: An interior door must connect the main dwelling and the ADU.
Size and Bedrooms: ADUs can have up to two bedrooms, must be 300-750 square feet, and if the main unit exceeds 3,000 square feet, the ADU can be up to 25% of the main unit's size.
Design Consistency: The ADU must be smaller, shorter, and consistent in appearance with the main dwelling.
Entrances and Exits: Additional entrances/exits for the ADU must be located on the side or rear. New structures must be behind the building line unless approved by the Zoning Board of Adjustment.
Parking: One parking space must be provided in the rear or side yard for the ADU, with no additional curb cut.
Ownership: The property cannot be converted to a condominium or any other separate legal ownership.
Permits and Safety: A zoning/building permit is required before construction, and a certificate of occupancy must be obtained before occupancy. The ADU must have an interconnected fire alarm system and meet all safety and building codes.