Zoning, building permits and septic rules in Town of Ossining, New York

Town of Ossining’s own rules

• Building permitRequired

  Buildings in any zoning district in the Town of Ossining's unincorporated area.

  • Proposed construction or use must conform to Chapter 200 and the Building Construction Ordinance.
  • A site-plan, conditional-use, or Board-of-Appeals approval must be obtained first when applicable.

  “No building in any district shall be erected, reconstructed, restored or structurally altered without a building permit duly issued upon application to the Building Inspector.”

• InspectionsRequired

  Town of Ossining zoning and building-code compliance in the unincorporated area.

  • The Building Inspector enforces Chapter 200 and rules, conditions, and requirements adopted or specified under it.

  “The following inspections are REQUIRED during construction.”

• Certificate of occupancyRequired

  Occupancy, use, or covered change of use of buildings and land in the Town of Ossining's unincorporated area.

  • Planning Board conditional-use or site-plan approval must be granted before a related certificate may issue.
  • Certificates connected with a conditional use, site-plan approval, or variance must state applicable conditions.

  “certificate of occupancy shall have been issued”

• Accessory dwellingsAllowed (with conditions)

  Accessory apartments within existing single-family homes or detached accessory buildings on single-family lots in the Town of Ossining.

  • An accessory-apartment special permit is required before any residential occupancy, use, establishment, maintenance, operation, rental, or lease.
  • The Zoning Board of Appeals may permit the apartment under the listed standards.

  “may permit the construction of an accessory apartment”

• Subdividing landRegulated (with conditions)

  Subdivision of land inside the Town of Ossining's unincorporated area.

  • Chapter includes procedures for sketch plans, minor-subdivision review, major-subdivision preliminary plats, final plats, required improvements, and filing approved plats.

  “the subdivider shall apply to the Board for approval.”

• Driveway accessRequired

  Lots proposed for construction or alteration of a building in the Town of Ossining's unincorporated area.

  • The cited rule concerns lot access to a street or highway; it does not establish a separate driveway-permit procedure.

  “No building permit shall be issued for the construction or alteration of any building upon a lot without access to a street or highway as provided in § 280-a of the Town Law of the State of New York.”

• Building in a floodplainRequired

  Construction or other development in Town-designated areas of special flood hazard.

  • Compliance with Chapter 102, Flood Damage Prevention, is required before a building permit issues in the described special-flood-hazard areas.

  “No building permit shall be issued for construction or any other development on property located in an area of special flood hazard [...] unless and until compliance with Chapter 102, Flood Damage Prevention, of the Code of the Town of Ossining shall be had.”

• Permit processPublished (with conditions)

  Building-permit applications in the Town of Ossining's unincorporated area.

  • Town page calls for completed, signed, notarized application, fee, and three sealed/stamped plan copies for covered construction or enlargement.

  “A completed, signed and notarized Building Permit application”

Rules another office applies inside Town of Ossining

Town of Ossining does not set these itself; the county, a health district or the state does, and they apply to every address inside its limits.

• Building code adoptedAdopted (with conditions)

  New construction, alterations, and permit applications inside the Town of Ossining's unincorporated area submitted on or after December 31, 2025.

  • Applications filed before December 31, 2025 are reviewed under the 2020 NYS Codes.
  • The town page says the 2020 NYS Codes were repealed and replaced with 2025 editions.

  2025 NYS Uniform Code and Energy Code compliance date: >= 2025-12-31 (New construction, alterations, and permit applications submitted on or after this date.)

  “must comply with the 2025 NYS Uniform Code and Energy Code.”

• Minimum dwelling sizeDistrict specific (with conditions)

  One-family residences in the Town of Ossining R-40 district.

  • Schedule applies to one-family residences in the listed districts.

  livable floor area per dwelling unit: 850 square feet (R-40 district)

  “BULK REGULATIONS FOR ONE-FAMILY RESIDENCES IN THE R-40, R-30, R-20, R-20A, R-15, R-10, R-7.5 and R-5 DISTRICTS”

• Minimum lot sizeDistrict specific (with conditions)

  One-family residences in the Town of Ossining R-40 district.

  • Schedule applies to one-family residences in the listed districts.

  minimum lot area: 40000 square feet (R-40 district)

  “BULK REGULATIONS FOR ONE-FAMILY RESIDENCES IN THE R-40, R-30, R-20, R-20A, R-15, R-10, R-7.5 and R-5 DISTRICTS”

• SetbacksDistrict specific (with conditions)

  One-family residences in the Town of Ossining R-40 district.

  • Schedule applies to one-family residences in the listed districts.

  front yard: 40 feet (R-40 district) · one side yard: 20 feet (R-40 district) · rear yard: 38 feet (R-40 district)

  “Front yard (feet) 40 [...] 1 side yard (feet) 20 [...] Rear yard (feet) 38”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Town of Ossining or Westchester County directly.

• Owner-builder exemption — Owner-builder construction inside the Town of Ossining's unincorporated area.
• Living in an RV — RV occupancy on private land inside the Town of Ossining.
• Camping on your land — Temporary camping on private land inside the Town of Ossining.
• Tiny homes — Tiny-home occupancy inside the Town of Ossining.
• Manufactured homes — Manufactured-home occupancy inside the Town of Ossining.

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Off-grid gear

Going off-grid in Town of Ossining means bringing your own water and power. The kit we’d start with:

• Water Crystal Quest Filter any source — well, rain, or creek — to drinking-clean.
• Power Bluetti Solar generators and home battery backup for living off the grid.
• Septic Soil percolation test kit Run your own perc test before paying an engineer — the first thing a septic office asks about.
• Water Well water test kit Bacteria, nitrates, hardness — know what the well on a parcel is really pumping.

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