Nahant

• Nahant uses a unique dual-definition approach: generic ADUs are prohibited in all districts, while Protected Use Accessory Dwelling Units (PADUs) meeting state law standards are permitted by right.
• PADUs are allowed in R-1, R-2, B-1, B-2, and P districts (not allowed in the NR district).
• All utilities servicing a PADU must be provided through the principal dwelling -- no independent utility connections.
• Short-term rentals are prohibited; minimum rental period is 3 consecutive months (90 days).
• Maximum 30 feet in building height for detached PADUs (Special Permit required for taller).

1. Verify PADU eligibility: Confirm your property is in an eligible zoning district (R-1, R-2, B-1, B-2, or P). PADUs are not allowed in the NR district.

2. Property owner consent: The application must be submitted by the property owner(s) of record and signed by 100% of the record title ownership interest. A copy of the deed must be included.

3. Prepare plans: Submit site plans, floor plans, and elevations to the Building Inspector showing proposed interior and exterior changes to existing buildings or new building and improvements on the lot.

4. Board of Health confirmation: The Board of Health must document to the Building Inspector that sewage disposal will be satisfactorily provided under Title V and local Board of Health regulations, including an appropriate reserve area. The combined bedroom/wastewater flow for both the principal dwelling and PADU must be met.

5. Additional permits (if applicable):

   • Conservation Commission review (if applicable)
   • Stormwater permits (if applicable)
   • Historic District review (if applicable)
   • Special Permit from ZBA (if detached PADU exceeds 30 feet in height)

6. Building permit: The Building Inspector issues the building permit for the PADU as a by-right use.

7. Construction: Must conform to the Massachusetts State Building Code and Title V of the State Sanitary Code, plus all applicable Nahant health, zoning, and other local laws.

8. Certificate of occupancy: Obtain before the PADU is occupied.

• Maximum size: 900 square feet or 50% of the gross floor area of the principal dwelling, whichever is smaller.
• Floor area exclusions: Garages, unfinished attics and basements, unenclosed porches and decks are not included in floor area calculations.
• No enlargement: Once a PADU has been added, it cannot be enlarged beyond the allowed square footage.
• Building/site coverage: Combined use of principal dwelling and PADU cannot exceed the maximum building or site coverage for the zoning district.
• Complete unit: Must contain both kitchen and bath as a complete, separate housing unit.
• Separate entrance: Required -- either directly from the outside or through an entry hall or corridor shared with the principal dwelling, sufficient to meet state building code requirements for safe egress.
• Detached PADU height: Maximum 30 feet. A Special Permit from the ZBA is required to exceed this height.
• Setbacks: Same as setbacks established in Nahant Zoning Bylaws for single-family dwellings.
• Utilities: All utilities servicing a PADU must be provided through the principal dwelling -- no separate, independent utility connections are permitted.

• One additional off-street parking space required for each PADU, in addition to any parking already required for the principal dwelling.
• No transit exemption specified: The Nahant bylaw does not include an explicit transit proximity exemption. However, under state law (760 CMR 71.03), no parking can be required for ADUs within 0.5 miles of a commuter rail station, subway station, ferry terminal, or bus station. Nahant is a small peninsula community; verify transit proximity with the Building Inspector.

• Dual ADU/PADU definition: Nahant's approach is unique -- generic ADUs are explicitly prohibited in all districts (marked "N" in the Table of Use Regulations). Only PADUs, which must meet the state law's Protected Use definition, are permitted (marked "P"). This means any ADU in Nahant must qualify under MGL c. 40A, Section 3.
• Utilities through principal dwelling: This is an unusual requirement. All utility connections (water, sewer, electric, gas) must run through the principal dwelling, not through independent connections. This may affect construction costs and design.
• 3-month minimum rental period: At 90 days, this is longer than the more common 30-day minimum seen in other North Shore towns. No boarding, lodging, short-term rental, or other commercial use is allowed (other than long-term rentals).
• Existing buildings only: The bylaw references PADUs within "a lawful existing Single-Family Dwelling" or "an existing detached building accessory to and on the same lot as the principal dwelling." This may be interpreted to limit PADUs to existing structures only, though state law requires municipalities to allow both attached and detached ADUs.
• Nonconforming ADUs can qualify: An ADU that is nonconforming to zoning can still qualify as a PADU if it otherwise meets the PADU definition. This provides a pathway for legalizing existing nonconforming units.
• Conservation, Stormwater, and Historic permitting: These additional requirements apply where applicable. Nahant is a coastal community, so environmental permitting may be a significant factor.
• Title V / Sewage: The Board of Health must confirm adequate sewage disposal, including a reserve area. Both the principal dwelling and PADU wastewater flow must be accounted for.
• No condo-ization: The lot and buildings cannot be placed in condominium form of ownership. The principal dwelling and PADU must remain in common or single ownership.
• Not a two-family dwelling: A PADU is explicitly not considered a two-family dwelling for zoning purposes.

The following is the full text of Nahant Zoning Bylaw Section 15: Protected Use Accessory Dwelling Units, as approved by the Planning Board on March 5, 2025.

SECTION 15: NAHANT PROTECTED USE ACCESSORY DWELLING UNITS

Section 15.01 - Purpose and Intent

The purpose and intent of this bylaw is to comply with Section 8 of Chapter 150 of the Acts of 2024, also known as the Affordable Homes Act.

Section 15.02 - Definitions

Accessory Dwelling Unit (ADU): A self-contained housing unit, inclusive of sleeping, cooking and sanitary facilities on the same lot as a principal dwelling, subject to otherwise applicable dimensional and parking requirements, that:

1. maintains a separate entrance, either directly from the outside or through an entry hall or corridor shared with the principal dwelling sufficient to meet the requirements of the state building code for safe egress;

2. is not larger in gross floor area than 1/2 the gross floor area of the principal dwelling or 900 square feet, whichever is smaller; and

3. is subject to such additional restrictions as may be imposed by a municipality, including, but not limited to, additional size restrictions and restrictions or prohibitions on short-term rental, as defined in section 1 of chapter 64G; provided, however, that Nahant shall not unreasonably restrict the creation or rental of a ADU that is not a short-term rental.

Protected Use Accessory Dwelling Unit (PADU): An attached or detached ADU that is located, or is proposed to be located, on a Lot in a Single-family Residential Zoning District and is protected by M.G.L. c. 40A, Section 3, provided that only one ADU on a lot may qualify as a PADU. An ADU that is nonconforming to Zoning shall still qualify as a PADU if it otherwise meets this definition.

Section 15.03 - Administration, Enforcement, and Procedural Requirements

1. The Building Inspector shall administer and enforce the provisions of this section.

2. The Nahant Zoning Board of Appeals shall be the Special Permit Granting Authority under this section and shall administer and enforce the provisions of this section related thereto.

3. To the extent applicable to a Single-Family Dwelling, the construction of any PADU must be in conformity with the State Building Code and Title V of the State Sanitary Code and lawful under all other provisions of applicable Nahant health, zoning and other local laws and regulations, including but not limited to all Conservation, Stormwater and Historic permitting requirements where applicable.

4. Prior to issuance of a building permit for a PADU, site plans, floor plans and elevations shall be submitted showing the proposed interior and exterior changes to existing buildings or new building and improvements on a lot associated with a proposed PADU.

5. Application for a PADU shall be submitted by the property owner(s) of record. The application shall be signed by one hundred (100) percent of the record title ownership interest of the principal dwelling and shall include a copy of the deed.

6. A PADU shall be permitted as a "By Right" use accessory to a lawful Single-Family Dwelling use.

Section 15.04 - Use and Dimensional Requirements

1. The PADU shall be a complete, separate housing unit containing both kitchen and bath.

2. The Building Inspector may issue a Building Permit authorizing the installation and use of a PADU within a lawful existing Single-Family Dwelling to which the PADU is accessory, or in an existing detached building accessory to and on the same lot as the principal dwelling subject to the following:

   a. Garages, unfinished attics and basements, unenclosed porches and decks shall not be included in the floor area calculations. Once a PADU has been added to a Single-Family Dwelling or lot, the PADU shall not be enlarged beyond the square footage allowed by this section. The combined use shall not exceed the maximum building or site coverage for the zoning district.

   b. The Board of Health must have documented to the Building Inspector that sewage disposal will be satisfactorily provided for in accordance with the provisions of Title V and local Board of Health regulations, including provisions for an appropriate reserve area on the site. The principal dwelling unit and PADU shall meet all wastewater requirements for the combined number of bedrooms / wastewater flow on the lot.

   c. A PADU is not intended for sale separate from the sale of the principal dwelling. The principal dwelling and PADU and lot on which they are located shall remain in common or single ownership, and shall not be severed in ownership, including that the lot or buildings thereon shall not be placed in a condominium form of ownership.

   d. No PADU shall be used for boarding and lodging, short-term rental, or other commercial use (other than long term rentals). A PADU may be rented for periods not shorter than a duration of three (3) consecutive months.

   e. Setbacks for PADUs shall be the same as setbacks established in the Nahant Zoning Bylaws for Single-Family Dwellings.

   f. Detached PADUs shall not exceed thirty (30) feet in building height (as defined in Section 2 - Height of Building) without a Special Permit.

   g. All utilities servicing a PADU must be provided through the Principal Dwelling and may not be provided through separate, independent utility connections.

   h. For each PADU, one additional off-street parking space shall be required in addition to any parking already required of the Principal Dwelling.

Section 15.05 - Prohibitions

1. No PADU may be sold separately from the principal dwelling.

2. No parcel may have more than one PADU thereon.

3. A PADU shall not be considered a two-family dwelling.

SECTION 4.13 - TABLE OF USE REGULATIONS (TABLE 1) (Amended)

N = Not Allowed P = Permitted

Generic ADUs are prohibited in ALL districts. Only PADUs (meeting state law definition) are permitted. PADUs are allowed in R-1, R-2, B-1, B-2, and P districts. Not allowed in NR.

Nahant has adopted the Stretch Energy Code. A certified HERS Rater is required for all new construction, including ADUs.

Your ADU must achieve a HERS index of 52 or lower (mixed-fuel) or 55 or lower (all-electric). Going all-electric earns a 3-point offset, making compliance easier. Budget $500–$1,500 for HERS testing.

ERV/HRV mechanical ventilation is now required (bath fans alone don't qualify). If on-site parking is provided, EV-ready wiring is also required.

Nahant's PADU bylaw was drafted specifically to comply with the state Affordable Homes Act (Section 8, Chapter 150 of the Acts of 2024). The bylaw is generally well-aligned with state law:

• By-right permitting: PADUs are permitted by right, consistent with state law.
• No owner-occupancy requirement: The bylaw does not impose an owner-occupancy requirement.
• Size limits consistent: 900 sq ft or 50% of principal dwelling, whichever is smaller, matches the state standard.
• One parking space: Consistent with the state maximum of 1 space.

Potential preemption issues to monitor:

1. Utilities through principal dwelling (Section 15.04.2.g): This requirement may be challenged as an unreasonable restriction on ADU creation, depending on how courts interpret state law.
2. 3-month minimum rental (Section 15.04.2.d): State law allows municipalities to restrict or prohibit short-term rentals. A 90-day minimum is more restrictive than the 30-day minimum in most other towns, but may be defensible as a reasonable restriction on short-term rental.
3. Existing buildings only: If interpreted to prohibit construction of new detached structures for PADUs, this could conflict with state law's requirement that municipalities allow both attached and detached ADUs. State law prohibits requiring that an ADU be attached or detached.
4. Transit proximity parking exemption: The bylaw does not explicitly include a transit exemption for parking. Under 760 CMR 71.03, no parking can be required for ADUs within 0.5 miles of transit.

• Nahant PADU Bylaw (approved March 5, 2025): https://nahant.org/wp-content/uploads/2025/03/ADU-By-law-approved-March-5-2025.pdf
• Town of Nahant ADU page: https://nahant.org/accessory-dwelling-units-adus/
• Town of Nahant website: https://nahant.org
• Massachusetts Affordable Homes Act (H.4977): https://www.mass.gov/info-details/accessory-dwelling-units
• 760 CMR 71.00 (Protected Use ADUs): https://www.mass.gov/regulations/760-CMR-7100-protected-use-accessory-dwelling-units