Off-Grid Living in Chilmark, Massachusetts

If you're dreaming of going off-grid on Martha's Vineyard, Chilmark is one of the more restrictive places to try it, at least on paper. Chilmark is fully zoned, so you're not dealing with the "wide open, do what you want" scenario you might find in some unzoned rural counties out west. I want to walk you through what I found researching this, and be upfront about where the town's records left gaps.

Zoning is administered by the Chilmark Planning Board and Zoning Board of Appeals, operating under the authority granted by Massachusetts General Laws Chapter 40A, Section 5. The town's bylaws (updated periodically by town meeting vote) include minimum lot sizes and a "large house" bylaw that ties house size to lot size, plus newer rules shaping accessory dwelling unit floor areas. This is not a place where you can just buy raw land and build whatever you want.

Dwellings, tiny homes, and RVs fall under that same zoning bylaw. I did not find Chilmark-specific language addressing tiny homes or an Appendix Q pathway (the state building code option some towns use for smaller dwellings), so I'd treat this as unconfirmed and call the Planning Board directly before committing to a design.

Building permits go through the town's Inspector of Buildings, currently Reade Kontje Milne, who applies the Massachusetts state building code (780 CMR). I didn't find local amendments beyond that baseline, but that doesn't mean none exist.

Septic and composting toilets are regulated locally by the Chilmark Board of Health, working within the state's Title 5 septic code (310 CMR 15.000). A Disposal System Construction Permit from the Board of Health is required before installation. Interestingly, Chilmark's Board of Health and Conservation Commission have been exploring urine-diverting eco-toilets, but the Massachusetts Department of Environmental Protection (MassDEP) currently has no regulatory pathway for these under Title 5, so that's not a viable option in town right now regardless of local appetite.

Greywater gets swept into the same Title 5 framework: state guidance says even if you're using a composting toilet, greywater from sinks and showers still needs a soil absorption system. Standalone greywater reuse isn't permitted here.

Rainwater harvesting has no Chilmark-specific rule that I could find. The general state baseline (outdoor collection generally fine, indoor plumbing use restricted) would apply by default, but confirm with the Board of Health or Building Inspector since local practice could differ.

Private wells are permitted but locally regulated by the Chilmark Board of Health, coordinating with state DEP standards. I couldn't locate the specific well siting text, so ask the Board of Health for their current requirements.

Utility disconnection (off-grid solar, etc.) requires permits through the Building Inspection & Zoning Enforcement office, including electrical inspection sign-off.

Bottom line: Chilmark is a well-regulated small town, not a legal grey zone. Call ahead before you buy land or build.