Home › Massachusetts › Lexington

Lexington, Massachusetts: what can you build or do?

Plain-English answers to common homeowner questions, taken from Lexington's published bylaws, with every rule linked to the section it comes from.

Last reviewed 2026-10-05

• Accessory Dwelling Units (ADUs)
  Yes. In Lexington's single-family districts (RO and RS) a basic accessory apartment inside your house is allowed by right if it's no more than 1,000 sq ft with up to two bedrooms; a larger apartment in the house or one in a detached accessory structure needs a special permit from the Board of Appeals. The bylaw we reviewed also requires the owner to live on the property, a rule state law may now override.Allowed
• Backyard Chickens
  Yes, for a small flock. Lexington's Board of Health regulations require a permit only to keep more than five small animals such as chickens, and that permit needs at least two acres. Any fowl whose crowing disturbs neighbors is prohibited, which in practice rules out most roosters.Allowed
• Short-Term Rentals (Airbnb / VRBO)
  Only if it's your primary residence (or the second unit on a two-unit lot where you live in the other one), and only after you register with Lexington's Building and Zoning Office, pass an inspection and pay the registry fee. Accessory apartments can't be used as short-term rentals, and stays when you aren't home are capped at 120 days a year.Restricted
• Fences
  Yes. Lexington's Zoning Bylaw lets you put a fence up to 6 feet high on or near a side or rear lot line, and up to 4 feet high on or near the front lot line, with posts allowed 6 inches above the fence. A taller fence inside a required yard must be set back from the lot line at least as far as it is tall.Allowed
• Sheds & Accessory Buildings
  Yes. In Lexington you can place one small shed (under 150 sq ft, no more than 12 feet tall or long) in a side or rear yard as close as 5 feet to the lot line. Larger sheds must meet the normal building setbacks, which in the RO and RS districts are 30 feet from the front and 15 feet from side and rear lot lines.Allowed
• Burn Permits & Backyard Fires
  Brush burning is allowed in Lexington only from January 15 to May 1, with a Fire Department permit obtained in advance, between 10 a.m. and 4 p.m., and at least 75 feet from any building or fence. You must call 781-698-4700 (option 8) after 9 a.m. on the day you burn to confirm burning is allowed.Allowed with a permit
• Home-Based Businesses
  Yes. In Lexington's residential districts, instruction and minor home occupations (no non-resident employees, no more than 2 visitors at a time and 6 a day) are allowed by right, while a major home occupation (one non-resident employee, up to 10 visitors a day) needs a special permit. No business signs, exterior storage or exterior alterations are allowed, and client visits are limited to 7 a.m. to 9 p.m.Allowed
• Swimming Pools
  Yes, with a building permit from Lexington's Building Commissioner. A swimming pool must be at least 20 feet from every lot line (or farther, if the district's building setback is greater), measured to the water's edge, and must have screening at least 5 feet high around it.Allowed with a permit
• Building Near the Water (Wetlands Rules)
  Work within 100 feet of a wetland, stream, pond or floodplain in Lexington needs a permit from the Conservation Commission under the town's wetland bylaw. The Commission's rules bar new structures, driveways or paving within 50 feet of a wetland except in extraordinary circumstances, and prohibit removing trees or shrubs within 25 feet.Allowed with board review
• Docks, Piers & Floats
  Lexington's bylaws and rules we reviewed don't specifically regulate private docks, piers or floats; Lexington is an inland town with no harbor rules. Any dock or float in a pond, stream or wetland would still need a Conservation Commission permit under the town's wetland bylaw, which covers building any structure or driving piling in those areas.Not specifically regulated