Salem

• Salem allows Affordable Accessory Dwelling Units (AADUs) by right under its locally adopted ordinance (Section 3.2.8), which predates the state ADU law.
• ADUs must rent at no more than 70% of HUD Fair Market Rent for Salem -- a unique affordability requirement enforced through a recorded deed restriction.
• Maximum size is 900 sq ft or 50% of the principal dwelling, whichever is smaller; minimum 350 sq ft.
• Attached, detached, and internal ADUs are all permitted across most residential districts (R1-R4, R5 for detached new construction, plus B1, B3, BPD).
• Short-term rentals of ADUs are prohibited. Owner-occupancy requirement was removed in May 2025 per state law compliance.

1. Confirm your property is in an eligible zoning district (R1, R2, R3, R4, R5, B1, B3, or BPD -- see use table for specific ADU types allowed per district).
2. Prepare architectural plans complying with building code, fire code, and health regulations.
3. Submit a standard building permit application to the Salem Building Department.
4. No special permit or public hearing is required (by-right approval).
5. Execute and record an affordability deed restriction limiting rent to 70% of FMR before certificate of occupancy is issued.
6. Pass all required inspections.
7. Obtain certificate of occupancy before occupancy or renting.

• Minimum size: 350 sq ft
• Maximum size: 900 sq ft or 50% of principal dwelling gross floor area, whichever is smaller
• Separate entrance: Required (may be a shared entry hall meeting building code egress requirements)
• Attached ADUs: Must maintain a single-family appearance from the exterior
• Detached ADUs: Height shall not exceed the height of the principal dwelling or the district maximum, whichever applies
• Setbacks: Must comply with zoning district setback requirements
• Lot coverage: Must comply with district lot coverage requirements
• One AADU per principal dwelling; must be on the same lot and clearly subordinate to the principal dwelling

• Maximum 1 additional parking space required for the ADU
• 0 parking spaces required if the property is within 0.5 miles of an MBTA station or bus stop (transit exemption)
• Parking requirements align with state law limits under 760 CMR 71.03

• Affordability Covenant: Salem is unique among North Shore communities in requiring ADU rents to be capped at 70% of HUD Fair Market Rent. As of FY2023, the 70% FMR maximums were: Studio $1,417.50/month, One Bedroom $1,538.60/month, Two Bedroom $1,844.50/month. These figures update annually based on HUD determinations.
• Historic District: Salem has significant historic districts (including Salem Common, McIntyre, Chestnut Street, Federal Street, Derby Waterfront). The source does not specify additional historic district review for ADUs, but applicants in historic districts should verify whether local historic commission review applies.
• Short-term rentals: ADUs may NOT be used as short-term rentals. Minimum rental period restrictions apply.
• 2025 Amendments: In May 2025, the Committee of the Whole voted to forward amendments removing owner-occupancy requirements and clarifying utilities/multiple ADU processes per state law compliance.

The following is the full text of Salem Zoning Ordinance Section 3.2.8 as captured from Municode:

SECTION 3.2.8 ACCESSORY DWELLING UNITS

Accessory Dwelling Units shall be allowed as provided set forth in this section.

1. Purpose.

a. To add rental units to the housing stock to meet the needs of smaller households and make housing units available to households who might otherwise have difficulty finding housing.

b. To encourage the efficient use of the city's housing supply while preserving the character of the city's neighborhoods.

c. To maximize privacy, dignity, and independent living among family members preserving domestic family bonds as well as to protect the stability, property values, and the residential character of the neighborhood.

d. To permit the owner of an existing, or a proposed, principal dwelling to construct one additional dwelling unit per principal dwelling. Such a use is incidental and subordinate in size to the principal dwelling.

e. To increase the supply of housing and the diversity of housing options, in response to demographic changes such as smaller households.

2. Definitions.

"Affordable Accessory Dwelling Unit" or "AADU" -- A secondary dwelling unit created on a lot with a principal dwelling. The AADU may be located within, attached to, or detached from the principal dwelling. The AADU is incidental and subordinate to the principal dwelling, and rents at no more than 70% of the applicable fair market rent limit established by HUD for Salem.

"Principal Dwelling" -- The primary, single-family residential structure on a lot.

3. Standards.

a. GENERAL:

• One AADU per principal dwelling
• Must be on same lot as principal dwelling
• AADU must be clearly subordinate to principal dwelling
• Minimum 350 sq ft
• Maximum: 900 sq ft or 50% of principal dwelling gross floor area, whichever is smaller
• Must have separate entrance (may be shared entry hall meeting building code)

b. AFFORDABILITY REQUIREMENT:

• Rent shall not exceed 70% of Fair Market Rent (FMR) for Salem as determined by HUD
• FY2023 FMR and 70% maximums:
  • Studio: FMR $2,025 / Max rent $1,417.50
  • One Bedroom: FMR $2,198 / Max rent $1,538.60
  • Two Bedroom: FMR $2,635 / Max rent $1,844.50

c. TYPES ALLOWED:

• Detached new construction ADU: Allowed in R1, R2, R3, R4, B1 districts
• Attached to principal dwelling or within principal dwelling: Allowed in R1, R2, R3, R4 districts
• Within existing detached accessory building: Allowed in R1, R2, R3, R4 districts

d. PARKING:

• Maximum 1 additional parking space required
• 0 parking spaces if within 0.5 miles of transit (MBTA station/bus stop)

e. DESIGN STANDARDS:

• Attached ADUs: Must maintain single-family appearance
• Detached ADUs: Height shall not exceed height of principal dwelling or district maximum
• Must comply with district setback requirements
• Must comply with lot coverage requirements

f. SHORT-TERM RENTALS:

• ADUs may NOT be used as short-term rentals
• Minimum rental period restrictions apply

g. OWNER-OCCUPANCY: [As of 2025 amendments, owner-occupancy requirement removed per state law compliance]

4. Permitting.

• Building permit required (standard process)
• No special permit required (by-right approval)
• Must comply with all building codes, fire codes, and health regulations
• Certificate of occupancy required before use

5. Affordability Covenant.

• The requirement that ADU rent not exceed 70% FMR is enforced through deed restriction
• The covenant must be recorded prior to issuance of certificate of occupancy
• Annual reporting of rental rates may be required

6. Severability. All the clauses of this ordinance are distinct and severable.

SALEM ADU USE TABLE (from Section 3.2 Accessory Uses):

Y = Allowed by right, N = Not allowed, BA = Board of Appeals special permit, PB = Planning Board special permit

2025 AMENDMENTS (per Committee of the Whole, May 2025):

Key changes recommended:

1. REMOVED owner-occupancy requirement (per state law compliance)
2. Clarified when utilities must be on separate services
3. Clarified process for multiple ADUs on same lot
4. Expanded circumstances for ADU construction

Salem has adopted the Specialized Opt-In Energy Code, the most stringent tier in Massachusetts. 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.

Additional Specialized Code requirements include ERV/HRV mechanical ventilation (bath fans alone don't qualify), EV-ready wiring if on-site parking is provided, and stricter standards for larger projects. All-electric construction is strongly encouraged.

Salem adopted its ADU ordinance in 2021, predating the state Affordable Homes Act. The ordinance was already relatively aligned with state law, but the following adjustment was made:

• Owner-occupancy requirement: Removed in May 2025 to comply with state law (760 CMR 71.03), which prohibits municipalities from requiring that the property owner occupy either the principal dwelling or the ADU.

Salem's affordability cap (70% FMR) is a more restrictive local provision but is generally considered permissible under state law because it regulates rental pricing rather than the creation or existence of ADUs. The state law prohibits "unreasonable restrictions on creation or rental" but an affordability cap is an economic condition on rental terms, not a barrier to ADU construction.

Other Salem provisions (size limits, parking, design standards, short-term rental prohibition) are consistent with what municipalities are allowed to regulate under 760 CMR 71.03.

• Salem Zoning Ordinance Section 3.2.8 (Municode): https://library.municode.com/ma/salem/codes/zoning_ordinance?nodeId=S3.0USRE_3.2ACUS
• City of Salem ADU Information Page: https://www.salemma.gov/adu
• Massachusetts Affordable Homes Act (H.4977 / St. 2024, c. 150)
• 760 CMR 71.00: Protected Use Accessory Dwelling Units