Amesbury

• Amesbury adopted a comprehensive ADU ordinance in October 2023 (Bill No. 2023-097), sponsored by Mayor Kassandra Gove, BEFORE the state Affordable Homes Act took effect. Several provisions are now preempted by state law.
• The ordinance uses distinct terminology: AADU (Attached Accessory Dwelling Unit) and DADU (Detached Accessory Dwelling Unit), with different design standards for each type.
• Under the original ordinance, AAADUs were by right and DADUs required a Planning Board Special Permit; under state law (effective Feb 2, 2025), all ADUs up to 900 sq ft are by right. The local 800 sq ft GLA maximum is also likely preempted.
• Design Review Committee oversight is required for architectural consistency -- this may still apply as a reasonable local design standard.
• A $20/SF GLA contribution to the Affordable Housing Trust is required for size waivers exceeding the base maximums. Maximum 2 bedrooms.

1. Prepare application: Submit a completed building permit application with plans showing ADU layout, dimensions, and relationship to principal dwelling; site plan showing lot boundaries, existing and proposed structures, parking, and access; and evidence of Title 5 septic compliance or municipal sewer connection.
2. Design Review Committee: The exterior design of the ADU must be reviewed by the Design Review Committee for architectural consistency with the principal building. Prepare materials addressing massing, scale, volume, architectural style, siding materials, window and door styles, trim details, and landscape screening.
3. Building Permit application: Submit to the Building Inspector. Under state law, conforming ADUs up to 900 sq ft are allowed by right (the original special permit requirement for DADUs is preempted).
4. Building Permit issuance: If the ADU meets all applicable standards, the Building Permit is issued.
5. Special Permit (if applicable): The Planning Board may still grant a special permit for ADUs that exceed the by-right standards (e.g., size waivers, dimensional waivers). The $20/SF GLA Affordable Housing Trust contribution applies to size waivers.
6. Post-approval: A certificate of use from the Planning Department is required to verify compliance. Owner-occupancy affidavit and annual verification requirements are preempted by state law.

All ADUs

• Maximum bedrooms: 2
• No commercial/business use: No business or commercial use may be conducted from an ADU.
• No separate ownership: The ADU shall not be held in or transferred into separate ownership from the principal dwelling.
• Parking location: One additional off-street parking space required, located behind the front wall of the principal building (except where existing parking for the principal dwelling is in front). No new parking in the required front yard setback.

Attached ADU (AADU) Standards

• Maximum size: 800 sq ft GLA (NOTE: likely preempted; state law allows up to 900 sq ft).
• Interior door: Required between the principal dwelling and the AADU.
• Subordinate appearance: The AADU must be subordinate to the principal dwelling in scale, height, and appearance:
  • If multiple front doors, one must be designed as principal and others as secondary.
  • Addition/expansion must be recessed or projected at least 18 inches from the existing front wall.
  • Attached, street-facing garage must be set back at least 10 feet from the front wall.
  • Height of any addition with increased footprint may not exceed 75% of the existing principal building height (single-story buildings may add a story or a single-story addition at the same height).

Detached ADU (DADU) Standards

• Maximum size: 800 sq ft GLA (NOTE: likely preempted; state law allows up to 900 sq ft). DADUs from existing non-conforming buildings may be up to 1,000 sq ft GLA.
• Maximum height: 22 feet.
• Maximum footprint: 750 sq ft.
• Maximum GFA: 1,500 sq ft or 75% of principal building GFA, whichever is less.
• Front wall setback: Must be set back at least 10 feet further from the front lot line than the principal building.
• Separation: At least 5 feet from the principal building (or as required by Building Code, whichever is greater).
• Height adjustment: If DADU is taller than principal building, required setbacks from all property lines increase by the height difference.
• Dormers: Allowed, but must be outside required setbacks and occupy no more than 50% of any individual roof plane.
• Existing non-conforming buildings: May not be expanded vertically or horizontally except for a front entry (up to 50 sq ft) or a side/rear deck (up to 150 sq ft). Planning Board may grant a special permit to expand GLA up to 1,000 sq ft.
• Privacy: No windows, balconies, or doors higher than 8 feet above grade facing adjacent property in side/rear yard setback areas.
• Drainage and lighting: Must comply with ordinance requirements.

Design Standards (All ADUs)

All ADUs are reviewed by the Design Review Committee. The exterior design must be architecturally consistent with or similar in appearance to the principal building with respect to:

• Massing, scale, and volume (including roof shape and type)
• Architectural style and overall appearance
• Siding material, texture, trim, and profile
• Window shape, type, spacing, proportions, and style
• Door style, material, and trim (street-facing garage doors limited to 9 feet in width)
• Projections (chimneys, cupolas, vents, bays, dormers, canopies, balconies)
• Trim details (window/door casings, cornices, soffits, eaves, dormers, shutters, railings)
• Exposed foundation materials and profiles
• Landscape buffers, fencing, or other screening for ground floor privacy

• 1 additional off-street parking space required for the ADU.
• Parking location: Must be behind the front wall of the principal building, except where existing parking for the principal dwelling is located in front. No new parking in the required front yard setback.
• Transit exemption: Under state law (760 CMR 71.03), no additional parking may be required for an ADU within 0.5 miles of a commuter rail station, subway station, ferry terminal, or bus station.
• Special permit modification: The Planning Board may modify parking requirements (including additional or reconfigured spaces) as part of a special permit for ADUs exceeding by-right standards.

• Pre-state-law ordinance: Amesbury's ADU ordinance was adopted in October 2023, before the state Affordable Homes Act. Several provisions are now preempted, creating a gap between what the local ordinance says and what is legally enforceable.
• AADU vs. DADU distinction: Amesbury is unique in using distinct terminology and standards for attached vs. detached ADUs. The different treatment (by-right for AADU, special permit for DADU) is preempted for ADUs up to 900 sq ft.
• 800 sq ft local cap: The 800 sq ft GLA maximum for both AADU and DADU is below the state law 900 sq ft standard and is likely preempted as unreasonably restrictive.
• Design Review Committee: The requirement for Design Review Committee review of architectural consistency is notable and may still apply as a reasonable design standard under state law. Homeowners should budget time and effort for this process.
• Affordable Housing Trust contribution: The $20/SF GLA contribution to the Affordable Housing Trust for size waivers is a unique local feature. This applies only to ADUs seeking a special permit to exceed base maximums, not to by-right ADUs.
• Historic preservation pathway: For adaptive reuse of a historic structure, a deeded preservation restriction may be offered as a public benefit in lieu of the $20/SF contribution for a size waiver.
• No home occupation with customer visits: An ADU cannot be on a lot where the principal dwelling has a home occupation involving customer, client, or patient visits.
• Post-approval certificate of use: The Planning Department requires a certificate of use to verify compliance. The owner-occupancy and annual verification components are preempted, but the general compliance verification may still apply.

Bill No. 2023-097

AN ORDINANCE TO AMEND THE AMESBURY ZONING ORDINANCE TO ALLOW ACCESSORY DWELLING UNITS (ADU) IN THE CITY OF AMESBURY

Sponsored by: Mayor Kassandra Gove

BE IT ORDAINED by the City Council of the City of Amesbury as follows:

SUMMARY OF AMENDMENTS:

1. Amend Section II: Definitions - to add definitions for ADU, AADU, DADU, Gross Living Area (GLA), and Gross Floor Area (GFA)
2. Amend Section IV: Zoning Map and Use Regulations - to add ADU as permitted use
3. Amend Section XI: Special Regulations - to add new Section XI.K.3 ADU provisions

Section I: Amend Section II - Definitions

ACCESSORY DWELLING UNIT (ADU): A self-contained residential dwelling unit located on the same lot, and subordinate in purpose to the principal or secondary dwelling unit. An accessory dwelling unit has an interior door connecting to the principal dwelling (AADU) or is a separate structure (DADU). An ADU shall provide independent living facilities for one or more persons including provisions for sleeping, cooking and sanitation.

ATTACHED ACCESSORY DWELLING UNIT (AADU): An accessory dwelling unit created within or added to an existing principal or secondary dwelling unit or building, with an interior connection to the principal dwelling.

DETACHED ACCESSORY DWELLING UNIT (DADU): An accessory dwelling unit in a building that is separate from, and subordinate to, the principal building or structure.

GROSS LIVING AREA (GLA): The total finished habitable floor area of an ADU, measured from the interior faces of exterior walls or from the centerline of walls separating the ADU from the rest of the building, excluding garages, unfinished basements, unfinished attics, enclosed porches, storage areas, shared entries, and similar spaces not exclusive to the ADU.

GROSS FLOOR AREA (GFA): The sum of the horizontal areas of the several floors of a building or structure measured from the exterior face of exterior walls or from the centerline of a common wall separating two buildings or uses, but excluding any space where the floor-to-ceiling height is less than six feet, six inches.

Section II: Amend Section IV - Zoning Map and Use Regulations

Table of Use Regulations amended to add:

• Accessory Dwelling Unit (Attached - AADU): Permitted by right (Y) in R1, R2, R3, OI
• Accessory Dwelling Unit (Detached - DADU): Planning Board Special Permit (SPP) in R1, R2, R3, OI

[NOTE: Under state law effective Feb 2, 2025, all ADUs up to 900 sq ft are by right. The special permit requirement for DADUs is LIKELY PREEMPTED.]

Section III: Amend Section XI - Special Regulations

New Section XI.K.3 - Accessory Dwelling Units

A. Purpose.

The purpose of this Section is to allow accessory dwelling units (ADUs) to increase the number of dwelling units available in the City of Amesbury while:

1. Ensuring consistency with the character and scale of existing neighborhoods
2. Preserving the long-term use and integrity of existing housing stock

A.2. Only one ADU shall be permitted for each principal or secondary dwelling unit located on a lot. An ADU shall not be permitted in conjunction with a home occupation that entails customer, client, or patient visits to the dwelling.

B. Eligibility.

B.1. An ADU may be located on any lot in a zoning district that permits single-family dwellings, provided the lot contains an existing principal or secondary dwelling unit or building.

B.2. Submission Requirements: Application for a building permit shall include:

• Completed building permit application
• Plans showing proposed ADU layout, dimensions, and relationship to principal dwelling
• Site plan showing lot boundaries, existing and proposed structures, parking, and access
• Evidence of Title 5 septic compliance or municipal sewer connection

C. Standards for All Accessory Dwelling Units.

C.1. An ADU shall not be held in, or transferred into, separate ownership from the principal or secondary dwelling unit.

C.2. Either the ADU or the principal dwelling unit shall be occupied by the property owner as the owner's principal place of residence. [PREEMPTED: State law effective Feb 2, 2025 prohibits owner-occupancy requirements.]

C.3. An ADU shall contain no more than two (2) bedrooms.

C.4. No business or commercial use shall be conducted from an ADU.

C.5. Prior to the issuance of a building permit, the owner shall demonstrate compliance with Title 5 septic regulations or connection to the municipal sewer system for the additional dwelling unit.

C.6. Off-Street Parking: One additional off-street parking space shall be provided for the ADU. Required parking for the ADU shall be located behind the front wall of the principal building or structure, except where the existing parking arrangement for the principal dwelling is located in front of the front wall. In no case shall new parking areas for an ADU be located in a required front yard setback.

D. Design Standards for All Accessory Dwelling Units.

Whether attached or detached from an existing principal building or structure, the exterior design shall be architecturally consistent with or similar in appearance to the principal building or structure using the following design standards which shall be reviewed by the Design Review Committee:

1. The new building or structure, addition, or expansion shall be architecturally consistent with or similar in appearance to the existing principal building or structure with respect to the following, but not limited to, elements:

   i. Massing, scale, and volume (including the roof shape and type). ii. Architectural style, and overall appearance. iii. Siding material, texture, trim, and profile. iv. Window shape, type, spacing, proportions, and style. v. Door style, material, and trim. All street-facing garage doors shall be limited to 9 feet in width. vi. Projections such as chimneys, cupolas, vents, bays, dormers, canopies, and balconies. vii. Trim details, including window and door casings, cornices, soffits, eaves, dormers, shutters, railings and other similar design elements. viii. Exposed foundation materials and profiles. ix. Landscape buffers, fencing, or other screen suitable for maintaining privacy at the ground floor level.

E. Additional Standards for Attached Accessory Dwelling Unit (AADU).

The following standards are intended to ensure proportionality and aesthetic continuity between the attached accessory dwelling unit (AADU) and the principal or secondary dwelling unit. An AADU shall comply with the following additional standards:

1. An interior door shall be provided between the principal dwelling unit and an ADU either within or attached to the existing principal structure.

2. The AADU, either within or attached to the existing principal structure shall not be larger than 800 sq. ft. in gross living area (GLA). For the purpose of this provision, the gross living area of the AADU shall not include storage space, shared entries, or other spaces not exclusive to the AADU. [NOTE: State law allows up to 900 sq ft. The 800 sq ft limit for AADU may be preempted as unreasonably restrictive.]

3. The AADU attached to the existing principal structure shall be subordinate to the principal dwelling unit in scale, height and appearance, as follows:

   i. If there are two or more doors in the front of the principal building or structure, one door shall be designed as the principal entrance and the other doors shall be designed to appear to be secondary.

   ii. An addition to or expansion of an existing building for the purpose of creating an AADU shall be recessed or projected at least 18 inches from the existing front wall of the principal building or structure. Where the addition includes the construction of an attached, street-facing garage, it shall be set back at least 10 feet from the front wall of the principal building or structure.

   iii. The building height of any addition or expansion that includes an increase in building footprint shall be no greater than 75% of the height of the existing principal building or structure. In the case of a single-story building, an addition or expansion may include either an additional story to the existing principal building or structure or a single-story addition at the same height as the existing principal building or structure.

F. Additional Standards for Detached Accessory Dwelling Units (DADU).

The following standards are intended to ensure proportionality and aesthetic continuity between the detached accessory dwelling unit (DADU) and the principal building or structure:

1. The DADU shall not be larger than 800 sq. ft. in GLA however, a DADU that is created from an existing accessory building that does not comply with its minimum yard requirements shall not exceed 1,000 sq. ft. in GLA. [NOTE: State law allows up to 900 sq ft or 50% of principal, whichever is smaller. The 800 sq ft base limit may be preempted; the 1,000 sq ft exception for existing buildings is more generous than state minimum.]

2. A DADU that is created from an existing accessory building that does not comply with its minimum yard requirements shall comply with the following additional requirements:

   i. The existing accessory building shall not be expanded either vertically or horizontally, other than through the addition of a front entry not to exceed 50 sq. ft., or a side or rear deck not to exceed 150 sq. ft.; except that the Planning Board may grant a special permit to allow the GLA of the accessory building to be expanded up to a total of 1,000 sq. ft. as provided in this Ordinance.

   ii. A DADU that is within a required side yard or rear yard setback for the zoning district shall not have any windows, balconies, or doors higher than eight feet above grade facing adjacent property. A corner lot shall have two front yards with the principal front yard being where the address is assigned.

3. The DADU shall be subordinate to the principal building or structure in scale, height and appearance as follows:

   i. The front wall of a DADU that is not created within an existing accessory building shall be set back at least 10 feet further from the front lot line than the existing front wall of the principal building or structure.

   ii. The building height of the building containing the DADU shall be no greater than 22 feet.

   iii. When the building containing the DADU is taller than the principal building or structure, its required setback from all property lines shall be increased by the difference in building height between the DADU and the principal building or structure.

   iv. The building footprint of the building containing the DADU shall be no greater than 750 sq. ft.

   v. The gross floor area (GFA) of the building containing the DADU shall be no greater than 1,500 sq. ft. or 75 percent of the GFA of the principal building or structure, whichever is less.

   vi. The DADU may include roof dormers provided they are located outside the required setbacks from all property lines and occupy no greater than 50% of any individual roof plane.

   vii. The DADU shall comply with the drainage requirements of this Ordinance.

   viii. The DADU shall comply with the lighting requirements of this Ordinance.

   ix. A newly constructed DADU shall be separated no less than 5 feet from the principal building or structure or as required by the Building Code, whichever is greater.

G. Special Permit Findings.

1. Section XI.K.3. requires a special permit for an attached or detached ADU, the Planning Board shall make the following findings before granting approval:

   i. The ADU complies with all applicable standards of this Section XI.K.3. or as may be modified by the special permit.

   ii. The exterior design of the ADU is architecturally consistent with or similar in appearance to the existing principal building or structure on the lot.

   iii. The site plan provides adequate and appropriate open space and landscaping for both the ADU and the principal building or structure and complies with the off-street parking requirements of Section XI.K.3.C.6.

   iv. The ADU will maintain a compatible relationship with the character of adjacent and neighborhood properties in terms of location, design, and off-street parking layout, and will not significantly reduce the privacy of adjacent properties.

   v. Except for the number of bedrooms, the Planning Board may waive any of the density or dimensional controls provided the Board finds such modification will be consistent with the required findings in Section XI.K.3.G and the applicant provides at least one of the following public improvements, including but not limited to:

   a. If applicable for the adaptive reuse of a historic structure, a deeded preservation restriction, as listed under Section XI.J.2.3-5, on the historic building or structure;

   b. For any increase in GLA over the maximums listed under Section XI.K.3.E-F, a contribution of $20/SF GLA to the Affordable Housing Trust; or,

   c. Off-site improvements to adjacent public infrastructure, such as sidewalks, drainage, or utilities.

2. In granting a special permit for an accessory dwelling unit, the Planning Board may modify or waive a specific standard set forth in Sections XI.K.3.C-F, including requiring additional or reconfigured off-street parking spaces, provided that the Board finds such modification will be consistent with the required findings in Section XI.K.3.G.

[NOTE: Under state law effective Feb 2, 2025, special permits cannot be required for ADUs up to 900 sq ft. The special permit provisions may only apply to requests exceeding by-right standards.]

H. Post-Approval Requirements.

1. Documentation of the special permit approval, including any project specific conditions, shall be recorded at the Essex County Registry of Deeds, together with an affidavit that either the principal or secondary dwelling unit(s) or the accessory dwelling unit will be occupied by the owner of the dwelling as the owner's principal place of residence, as required by Section XI.K.3.C.2. [PREEMPTED: Owner-occupancy affidavit requirement preempted by state law.]

2. A certificate of use issued by the Planning Department is required to verify compliance with the standards of this Section, including the owner-occupancy and principal residency requirements. Said certificate shall be issued by the Planning Department upon issuance of a certificate of occupancy by the Inspection Department. A certificate of use shall not be issued prior to recording of documentation as required by this Ordinance. [PREEMPTED IN PART: Owner-occupancy verification preempted by state law.]

3. The certificate of use shall be renewed annually upon submission of such documentation. The Planning Department may require the owner to verify continued compliance with the standards of this Section. Failure to comply with this requirement shall be deemed a violation of the ordinance and may be enforced as provided in Section X.

Amesbury 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.

Amesbury's ADU ordinance (Bill No. 2023-097) was adopted in October 2023, before the Massachusetts Affordable Homes Act took effect on February 2, 2025. The following provisions are preempted by state law:

1. Owner-occupancy requirement (Section XI.K.3.C.2): State law prohibits municipalities from requiring owner-occupancy of either the ADU or the principal dwelling.
2. Owner-occupancy affidavit/deed recording (Section XI.K.3.H.1): The requirement to record an owner-occupancy affidavit at the Registry of Deeds is preempted.
3. Annual owner-occupancy verification (Section XI.K.3.H.2-3): The annual certificate of use renewal with owner-occupancy verification is preempted.
4. Special permit for detached ADUs (Use Table): The requirement for a Planning Board Special Permit for DADUs is preempted for ADUs up to 900 sq ft. All such ADUs must be allowed by right.
5. 800 sq ft GLA maximum (Sections XI.K.3.E.2 and F.1): The 800 sq ft cap for both AADU and DADU is below the state law 900 sq ft standard and is likely preempted as unreasonably restrictive.

Provisions that may still apply as reasonable local regulations:

• 2-bedroom maximum (may be reasonable)
• 1 parking space with location restrictions (consistent with state law)
• Design Review Committee review (may be reasonable as a design standard)
• Septic/Title 5 compliance
• No separate ownership
• No commercial/business use in ADU
• DADU height maximum of 22 feet
• DADU footprint maximum of 750 sq ft
• DADU subordinate appearance standards
• $20/SF GLA Affordable Housing Trust contribution for size waivers (applies only to above-by-right requests)
• Privacy protections (no windows above 8 ft in setback areas)
• 5 ft minimum separation from principal building

• Amesbury ADU Ordinance (Bill No. 2023-097): https://www.amesburyma.gov/DocumentCenter/View/4228/2023-097-An-Ordinance-to-amend-the-Amesbury-Zoning-Ordinance-to-alllow-Accessory-Dwelling-Units-ADU-in-the-City-of-Amesburypdf
• City of Amesbury official website: https://www.amesburyma.gov
• Massachusetts Affordable Homes Act (H.4977 / St. 2024, c. 150): https://www.mass.gov/info-details/accessory-dwelling-units
• 760 CMR 71.00 (Protected Use Accessory Dwelling Units): https://www.mass.gov/regulations/760-CMR-7100-protected-use-accessory-dwelling-units