NH HB1136

Municipalities must allow one accessory dwelling unit (ADU) per single-family dwelling in all zones permitting single-family homes, either by right, conditional use permit, or special exception, and may optionally allow more than one ADU per dwelling

Removes the previous requirement that one ADU be allowed "as a matter of right" and permits municipalities to require familial relationships between ADU and principal dwelling occupants, as well as require ADUs meet workforce housing affordability standards

Municipalities may establish minimum and maximum size limits for ADUs but cannot restrict living space to less than 750 square feet; detached ADUs are capped at 950 square feet unless locally authorized

Allows municipalities to prohibit ADUs associated with townhouses, manufactured housing, or rented/leased land, and prohibits separate condominium conveyance of ADUs unless the municipality expressly permits it

Existing structures like detached garages may be converted to ADUs, but municipalities may require compliance with local zoning ordinances before conversion; the act takes effect July 1, 2026