ADU Rules: Arlington vs Newton
How do adu rules rules compare between Arlington, MA and Newton, MA?
Arlington and Newton have similar restriction levels.
Arlington, MA
Middlesex County
Under the 2024 MA Affordable Homes Act (MGL c.40A s.3A), ADUs up to 900 sq ft are allowed by-right on every single-family lot in Middlesex County. No owner-occupancy or special permit required.
View full Arlington rules →Newton, MA
Middlesex County
Newton allows ADUs by right on most residential lots under MGL c.40A s.3A (Affordable Homes Act 2024); Newton has actively embraced ADUs as housing strategy.
View full Newton rules →Key Facts Comparison
| Fact | Arlington | Newton |
|---|---|---|
| State Law | MGL c.40A s.3A (Feb 2025) | MGL c.40A s.3A (2024) |
| Max Size | 900 sq ft or 50 percent | 900 sf or 50 pct |
| Owner-Occupancy | Not required | - |
| Parking Max | 2 spaces max | - |
| Review Type | By-right, no special permit | - |
| Parking | - | One space typical |
| Short-Term Rental | - | Prohibited |
| Owner Occupancy | - | Required |
Highlighted rows indicate differences between cities.
Arlington FAQ
Can I build an ADU on my lot in Middlesex County?
Yes. As of February 2025, the Affordable Homes Act requires all MA municipalities to allow ADUs by right on single-family lots up to 900 sq ft.
Do I have to live on the property?
No. The statewide ADU law prohibits owner-occupancy requirements, so you can rent both units.
Newton FAQ
Can I build an ADU on my Newton single-family lot?
Yes. ADUs are allowed by right in Newton under the MA Affordable Homes Act and local zoning, up to 900 sf with standard building permits.
Can I Airbnb my Newton ADU?
No. ADUs cannot be used for short-term rentals under 31 days under the MA ADU framework and Newton short-term rental rules.
Compare other topics
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