Hollis, New Hampshire

Hollis, NH Accessory Dwelling Unit (ADU) Rules

City Acceptance Rating: 8/10

Last Updated: 8.28.2024

Image Source: Town of Hollis

What You Need To Know

ADUs must be secondary to the main house and maintain the home's single-family appearance with new entrances placed on the side or rear. ADUs should be 300 to 800 square feet, not exceed 30% of the main home's floor area. ADUs cannot be used for short-term rentals except for Bed and Breakfasts.

Type of ADU Permit Required

ADUs are permitted by special exception from the Board of Adjustment in any district, following these regulations.

ADU Rules

  • Secondary Unit: ADUs must be secondary to the main house and must not change its appearance as a single-family home. Only one ADU is allowed per house and lot, and it must have its own house number.

  • Exterior Changes: Any exterior changes should not alter the look of the home. New entrances should be placed on the side or rear.

  • Lot Size: ADUs don’t require extra lot size beyond what’s needed for the main house.

  • Detached ADUs: Detached ADUs are allowed only on larger lots and cannot be converted into main houses.

  • Size: ADUs must be between 300 and 800 square feet and take up no more than 30% of the total floor area.

  • Integration: Attached ADUs should be easy to merge back into the main house and must share an internal connection.

  • Septic System: The septic system must be certified to handle the additional waste. If the current system isn’t adequate, it must be upgraded.

  • Parking: There must be enough off-street parking for both units.

  • Access: The property must allow safe entry and exit for vehicles.

  • Use Restrictions: ADUs cannot be used for short-term rentals like hotels or motels, except for Bed and Breakfasts.

Resources:

https://www.hollisnh.org/sites/g/files/vyhlif3271/f/uploads/holliszoningordinance2024_0.pdf page 14

Attached ADU, Convert Existing Space, Detatched ADUDeanna DuffeyNew Hampshiure, Friendliness Rating 8/10, Hollis