Chatham ADU Regulations
Current zoning bylaws, requirements, and permit process for Accessory Dwelling Units in Chatham, Massachusetts. Last updated: October 2025.
Please Note: This information is provided for general informational purposes only and should not be considered legal or professional advice. ADU regulations are subject to change, and individual circumstances may vary. We strongly recommend verifying all requirements, zoning bylaws, and permit procedures directly with the Town of Chatham Building Department or Planning Board before beginning any planning or construction activities. Town officials can provide the most current regulations and guidance specific to your property and project.
Bullet Point Summary
- Maximum Size: 900 sq ft or 50% of primary dwelling (state minimum applies) }
- Owner Occupancy Required: No (prohibited by state law)
- Number of ADUs Permitted: One by-right per property
- Attached vs. Detached: Both allowed
- Parking Requirements: Max 1 space (state limit)
- Design Requirements: Must comply with local dimensional standards
- Septic/Title 5 Requirements: Title 5 compliance required
- Rental Restrictions: Title 5 compliance required
- Special Incentives: None identified
- Application Process: Building permit through Building Department
Additional Information
For the most up-to-date and complete regulations, please contact the Chatham Building Department at 508-945-5160 or visit the town's official website at chatham-ma.gov.
Our ADU specialists can help you navigate Chatham's specific requirements and design an ADU that meets all local regulations while maximizing your property's potential.