Off-Grid Living in Lexington, Massachusetts

I'll be upfront: Lexington, Massachusetts is about as far from "off-grid friendly" as you'll find in my research files. This is a fully zoned, tightly regulated Boston-suburb town, and every layer of government here (state, county-equivalent, and town) has a say in what you can build and how you can live.

Zoning. Lexington's Zoning Bylaw (Chapter 135 of the Town Code, administered by the Building Department) divides the entire town into residential and commercial districts with dimensional rules on setbacks, frontage, height, and lot coverage. There's no agricultural or unrestricted zone where you could just plant a cabin on raw land. In fact, the bylaw specifically says no structure other than a solar energy system can go up on a lot lacking the minimum frontage for its district.

Dwellings, tiny homes, RVs. Lexington has its own accessory dwelling unit (ADU) rules layered on top of the 2024 Massachusetts ADU law, and any ADU needs an Accessory Apartment Building Permit through the town's online system. Worth noting: Lexington hasn't yet updated its bylaw for the state's new "Protected Use ADU" category, so some state exemptions may apply even where town code hasn't caught up, ask the Building Department for the current interpretation. I found nothing allowing an RV or tiny home as a standalone permanent residence on vacant land, and that's genuinely unconfirmed rather than a clear "no."

Building permits. All one- and two-family homes are subject to Lexington's dimensional schedule (Chapter 135, Table 2), including a height cap around 2.5 stories. The Building Department issues permits and can revoke a certificate of occupancy if a property stops complying.

Septic and composting toilets. Septic falls under Massachusetts Title 5 (310 CMR 15.000), enforced locally by the Lexington Board of Health, and Lexington has added its own well-setback rules that reference septic locations (75 feet from a septic tank, 150 feet from leaching fields, for example). Composting toilets need a System Construction Permit from the Board of Health under state guidance; I couldn't confirm any Lexington-specific add-ons.

Greywater and rainwater. I found no Lexington bylaw on either topic. That means you're likely working from the state Title 5 baseline, which treats greywater as wastewater needing an approved absorption system. Rainwater harvesting for outdoor use doesn't appear to be locally addressed at all; not confirmed either way.

Private wells. This is where Lexington gets notably strict, with its own Article X well regulations exceeding state minimums, including a 10-foot property-line setback, 25 feet from roads, and no use of an irrigation well until the Board of Health signs off on final inspection.

Off-grid utilities. No outright ban on disconnecting from the electric grid, but any dwelling still has to pass Certificate of Occupancy and building code review.

Bottom line: confirm everything directly with the town before you plan anything here.