Watertown Weighs ADUs as Square Zoning Advances
Watertown, MA – March 15, 2026 – Accessory dwelling unit rules and Square zoning updates highlight ongoing efforts to expand housing options.
Watertown, MA continues to focus on adding housing through zoning updates and small-scale infill as state requirements reshape local rules.
Top takeaways
- Community discussion underway on how accessory dwelling units (ADUs) should be allowed under state law.
- Watertown Square zoning enables thousands of potential new units over time.
- Planning staff remain active with permits, design review and redevelopment studies.
ADUs in the spotlight
A recent community dialogue highlighted how the state’s Affordable Homes Act requires cities and towns to allow certain ADUs by right in single-family districts. Local officials and housing advocates have discussed how Watertown can implement the law while addressing neighborhood concerns such as parking, scale and infrastructure.
The shift could open the door to more backyard cottages, in-law apartments and internal conversions, offering incremental supply without large redevelopment.
Watertown Square buildout
Separately, zoning changes tied to the MBTA Communities law have positioned Watertown Square for significant long-term growth. Local commentary in February noted that zoning in the Square now allows for more than 3,000 housing units, exceeding the state’s minimum requirement of 1,701 units.
Through 2025–2026, consultants are studying redevelopment potential of key parcels, with further approvals required before projects advance to construction.
Permits and next steps
The Planning & Zoning Department continues to process land use permits and oversee design review. As proposals move from concept to formal application, public meetings and hearings will shape building height, sustainability standards and public benefits.
For homeowners considering renovations or additions, local ServiceXTC providers include: F.H. Perry Builder (home builder), Stella Construction & Home Services (remodeler), Addario’s Services (plumbing & HVAC), and McCarthy Electric (electrician).
Sources
What changes are you seeing in your neighborhood — more small additions, or larger redevelopment proposals?