On April 22, the City Council approved two separate sets of amendments to Newton’s Accessory Dwelling Units (ADU) ordinance. The first set, which passed unanimously, aligns Newton’s zoning with a new State Law allowing ADUs of up to 900 square feet by right. That state law had invalidated these old Newton ADU requirements:
- The property owner or an indirect property owner had to occupy either the principal dwelling unit or the accessory apartment.
- An annual, notarized affidavit had to be filed with the Commissioner of Inspectional Services, attesting to the continued owner occupancy of the property.
- ADUs could not be in historic carriage houses in Historic Districts.
- A setback of 15 feet which was required between a carriage house ADU and another structure.
The second set of changes, proposed by Councilor Albright and approved by a vote of 18-6, went beyond the state’s ADU requirements. The six Councilors who voted against the amendment wanted the additional protection for abutters of an owner-occupancy requirement for external, separate ADUs of over 1,000 square feet built with special permits or as existing building conversions.
The net result of both sets of changes is that:
- New internal ADUs within the main residence are allowed by right up to 1,000 sq ft (or 1200 sq ft for existing converted ADUs) as long as the ADU is not more than 50 percent of the floor area of the main building.
- Detached ADUs are allowed up to 1,000 sq ft by right, or up to 1500 sq ft by special permit, and up to 1.5 stories or 22 feet in height.
- Carriage houses and other historic accessory buildings may include ADUs by right.
- There may be only one ADU per lot, and ownership of the ADU and main residence must be the same.
- The minimum rental or occupancy term is 30 days.
- No additional parking is required.
- There is no requirement for by-right ADUs to be screened, but ADUs by special permit may be subject to screening requirements.
Newton’s Accessory Dwelling Units (ADU) ordinance was first passed in 1987. It was updated in 2017 and 2022. Newton currently has 33,116 housing units and 121 legally permitted ADUs.
Previous Fig City News articles on Newton’s ADU ordinance:
- Amendments proposed to Accessory Dwelling Unit Ordinance, by Amy Sangiolo on August, 15, 2022
- City Council passes ADU amendments, by Amy Sangiolo on October 17, 2022
- In working session, Zoning and Planning committee discusses amendments to ADU ordinance, by Theo Younkin on March 11, 2025
