Lexington, MA
Lexington, MA Accessory Dwelling Unit (ADU) Rules
City Acceptance Rating: 7/10
Last updated: 6.19.2024
Image source: Yankee Magazine
What You Need To Know
ADUs are permitted in Lexington with the purpose of increasing available housing units and the range of housing options as well as encouraging a diverse population and encouraging a more energy-efficient and economic housing stock.
Type of ADU Permit Required
A special permit is required in Lexington to build an ADU.
ADU Rules
There is only one ADU permitted per lot.
The owner of the primary dwelling must live in either the primary dwelling or the ADU.
If the owner is away from the property for less than two years, both the primary dwelling and ADU may be rented as long as:
Notice is given to the Building Commissioner
The owner must reside on the property at least two years before and after such leave
The ADU must be designed in a way that maintains the appearance of a single family dwelling and meet the following criteria:
All stairways must be enclosed
Only one door can have the appearance of a principal entrance
Lexington distinguishes between three different ADUs
Basic ADU
Maximum of 1,000 square feet for gross floor area
There cannot be greater than two bedrooms
The ADU must be located in the primary dwelling
Expanded ADU
The gross floor area cannot be greater than 40% of the gross floor area of the primary dwelling
The ADU is designed so that it is consistent with the appearance of a single family home
The ADU must be located in the primary dwelling
Accessory Structure ADU
This is an ADU in an accessory structure, i.e. a garage
Maximum of 1,000 square feet for gross floor area
The ADU is designed so that it is consistent with the appearance of a single family home on that lot and surrounding lots
Resources:
Zoning By-law of the Town of Lexington- Section 6.7/Page 58
https://www.lexingtonma.gov/DocumentCenter/View/7684/Zoning-Bylaw-PDF