Off-Grid Living in Putnam County, New York

I've spent some time digging through Putnam County, New York's official pages and a few town sites, and the first thing worth understanding is the structure: Putnam County itself does not zone land and does not run a countywide building department. That surprises people. Zoning, building permits, and certificates of occupancy are all handled town by town, by whichever of the six towns your parcel sits in (Carmel, Kent, Patterson, Philipstown, Putnam Valley, or Southeast). The county's real regulatory muscle is in environmental health, specifically septic systems and private wells, through the Putnam County Department of Health (PCDOH), which enforces the Putnam County Sanitary Code.

Zoning and dwellings. Since there's no county zoning code, whether you can put a tiny home, RV, or off-grid cabin on a piece of land depends entirely on that town's zoning ordinance and building department. I found nothing at the county level addressing tiny homes or RVs specifically, so this is a "go ask your town" situation, not a county one.

Building permits. Again, towns issue these, and they follow the New York State Uniform Fire Prevention and Building Code as the baseline, with towns like Putnam Valley layering their own zoning ordinance on top. Putnam Valley's code office noted that starting in 2026, plans need to comply with the newer 2025 state code cycle, which gives you a sense that these codes shift over time, so always confirm current requirements directly with the town.

Septic. This is squarely a county function. PCDOH administers septic permitting and repair approvals under the Sanitary Code, requires soil test pits or percolation tests witnessed by their engineering staff, and, notably, properties in the NYC watershed or near certain impaired water bodies (like Oscawana Lake) face a mandatory five-year septic inspection and cleaning cycle tied to a 2011 state MS4 requirement. Composting toilets aren't addressed separately on the county's site, so I'd confirm with PCDOH whether one satisfies their requirements or whether you still need a conventional septic system approved.

Wells. PCDOH requires a permit before any well is drilled, and this extends to ponds and existing wells being newly connected to a dwelling. Fees are apparently based on population served, though no dollar figures were listed anywhere I could verify, so ask PCDOH directly.

Greywater and rainwater aren't addressed by any Putnam County ordinance I could find. Absent local rules, state plumbing code defaults likely apply to greywater, and there's no dedicated NY statute for rainwater harvesting yet. Treat both as unclear and confirm with PCDOH or your town before building a system.

Utilities. No county rule forces grid connection, but because towns generally require an approved water supply and septic system before issuing a certificate of occupancy, full off-grid living (no PCDOH-approved water/waste system) can become a practical barrier even if the wording never says "grid required."

Bottom line: figure out your town first, then loop in PCDOH for anything touching water or waste.