ADU Zoning in Greenwich, Connecticut
What Greenwich allows for accessory dwelling units — permitted zones, size limits, parking, rental rules and utilities. Boxx ADUs designs and builds ADUs in Greenwich and across Fairfield County. Call us to talk through your property, or send us a message.
Which zones allow ADUs?
In RA-4, RA-2, RA-1, R-20, R-12, and R-7 zones, both detached and attached ADUs are allowed. There is no minimum lot size requirement for ADUs.
What types of ADUs are allowed?
Attached, Detached, or Converted ADUs
What are the size/floor area requirements?
The maximum floor area for detached ADUs is 700 sq. ft., but this can be increased to 800 sq. ft. if there is a demonstrable need.
Accessory Apartments shall not exceed 1,200 square feet in floor area or 35% of the primary home’s square footage, whichever is less. Max Height is 25 feet.
How many parking spaces?
Greenwich requires one parking space per Accessory Apartment. If you plan to add an ADU to a Greenwich property, plan to accommodate three parking spaces within the bounds of your property.
What are the rental requirements?
Long-term and short-term rentals are allowed.
Owner-occupancy is required.
What about utilities, sewer or septic?
Utilities and sewer tie into the main house. Septic is job-specific.
Summarized for convenience and current as of publication. Local regulations change — confirm details with the town before relying on them.