Off-Grid Living in Brentwood, New Hampshire

Brentwood, New Hampshire is a zoned town, so if you're picturing a wide-open patch of land where nobody asks questions, that's not quite the reality here. The Town has an adopted Zoning Ordinance enforced by the Zoning Board of Adjustment and a Planning Board that maintains the Master Plan and recommends ordinance changes, all under the state's zoning enabling law (RSA 674). Any off-grid plan in Brentwood starts with checking your parcel's zoning district and, if you want to do something unusual, expect to deal with the ZBA for a variance or special exception.

On dwellings, tiny homes, and RVs: I could not find Brentwood-specific ordinance language addressing these directly in my research. That doesn't mean anything goes, it means the answer lives inside the general Zoning Ordinance and Building Inspector's interpretation, and you'd need to ask the Building Inspector's office directly how they'd classify a tiny house or RV as a permanent residence.

Building permits are handled locally. The Town's own page notes that permit applications are available at the Town Office and that building permit applications are approved by the Selectboard, with inspections and plan reviews done by appointment. So yes, you'll need a permit for most construction, and the process runs through Town Hall, not the state.

Septic is where state authority takes over. New Hampshire DES requires that any structure connected to a water supply also be connected to an approved wastewater disposal system, either sewer or an individual sewage disposal system (ISDS). Plans have to be designed by a state-permitted septic designer, and DES issues both a Construction Approval and later an Operation Approval before you can use the system. Brentwood doesn't appear to have its own separate septic ordinance beyond deferring to this state process, though the Planning Board can weigh in through subdivision or site plan review.

Composting toilets, greywater reuse, and rainwater harvesting are all areas where I found no Brentwood-specific rules. These likely default to whatever New Hampshire's statewide code allows (the state's adopted residential and plumbing codes do permit some indoor non-potable rainwater use), but I'd confirm specifics with the Building Inspector before assuming.

Wells fall under the state Water Well Board's rules rather than any separate Brentwood ordinance. DES septic application forms do require disclosure of well location and radius, so your well and septic system plans are reviewed together in effect.

On living fully off-grid, the real trigger point is water. If you never connect a water supply, you avoid the state's mandatory wastewater-connection rule. Bring in a well, though, and you need an approved septic or ISDS system. No additional Brentwood utility-hookup mandate turned up in my research.