Accessory Dwelling Units (ADUs) in Arlington, MA
Arlington has proactively embraced Accessory Dwelling Units (ADUs) as a solution to address housing affordability and diversity. With the implementation of the Affordable Homes Act, homeowners in Arlington have new opportunities to add ADUs to their properties.
Here's what you need to know about building an ADU in Arlington as of 2025.
Statewide ADU Regulations: The Affordable Homes Act
In August 2024, Massachusetts enacted the Affordable Homes Act, a significant piece of legislation aimed at addressing the state's housing shortage. A key provision of this act is the allowance of ADUs by right in single-family zoning districts.
Key provisions include:
By-right ADUs: Homeowners can build ADUs without needing special permits, provided they meet certain criteria.
Size limitations: ADUs must be no larger than 900 square feet or 50% of the primary dwelling's gross floor area, whichever is smaller.
No owner-occupancy requirement: Municipalities cannot mandate that either the main house or the ADU be owner-occupied.
Parking requirements: No additional parking is required if the property is within 0.5 miles of public transit.
These regulations aim to streamline the process for homeowners and encourage the development of diverse housing options across the state.
Arlington's Local ADU Policies
Prior to the Affordable Homes Act, Arlington had already adopted an ADU policy in its Zoning Bylaw, allowing attached or detached units of no more than 900 square feet. While specific details of the local ordinance are not provided here, it's essential to note that any local regulations conflicting with the state law are now overridden. (Accessory Dwelling Units (ADUs) | Town of Arlington)
For instance, if Arlington previously required owner occupancy for ADUs, such a requirement is no longer enforceable under the new state law. Homeowners should consult the Arlington Inspectional Services Department or local zoning office to understand any remaining local provisions that align with the state law.
Community Sentiment & Local Implementation
Arlington has demonstrated a commitment to increasing housing diversity and affordability. The town has actively engaged residents through informational webinars and partnerships with local organizations to promote understanding and adoption of ADUs.
In 2024, the town collaborated with the Housing Corporation of Arlington to install an all-electric, modular accessory dwelling unit, showcasing a commitment to sustainable and affordable housing solutions. (Arlington, nonprofit team up on environmentally friendly ADU)
While there is general support for ADUs as a means to address housing challenges, some residents have expressed concerns about potential impacts on neighborhood character and infrastructure. The town continues to engage with the community to address these concerns and ensure that ADU implementation aligns with Arlington's values and goals.
What This Means for Homeowners in Arlington
If you're a homeowner in Arlington considering adding an ADU to your property, here's what you should know:
Permitting: With the Affordable Homes Act, you can build an ADU by right, eliminating the need for special permits, provided your project meets the stipulated criteria.
Design considerations: Ensure your ADU design complies with both state and any applicable local regulations, especially concerning size and setbacks.
Consult local authorities: While state law provides overarching guidelines, it's crucial to consult Arlington's local planning or zoning department for any additional requirements or recommendations.
Get a Custom ADU Roadmap for Your Property
Considering building an ADU in Arlington? We offer a comprehensive ADU Roadmap Report tailored to your property. This includes:
Site visit and feasibility analysis
Cost estimation and timeline
Guidance on permitting processes
Rental income projections
Contractor referrals
👉 Schedule Your ADU Roadmap Consultation
Note: For the most accurate and up-to-date information on Arlington's ADU policies, please refer to the official town documents or contact the local planning department directly.
