Building permits, zoning and septic rules in Montgomery County, New York

At a glance

Building permit

Required, but issued by the town, village or city, not the county¹²

Zoning

No county-level zoning; each town, village or city zones its own land³

Septic system

Approval authority not confirmed; new systems must meet statewide standards and may need health-department approval⁵⁴

Owner-builder exemption

Not confirmed for this county; ask your town's code office⁶

Occupancy certificate

Required for work covered by a building permit⁷

Building code

The 2025 New York Uniform Code is in effect; fossil-fuel prohibitions remain suspended⁸

RV or tiny home

Set by each municipality; the Town of Mohawk limits travel-trailer residency⁹

Who to call

Contact details are copied from each office’s official page and were checked against it on October 9, 2026.

Do you need a building permit in Montgomery County, New York?

Yes. Work that must comply with New York's Uniform Code or Energy Code requires a building permit from the local authority having jurisdiction². In Montgomery County, the municipality where the parcel lies administers that requirement¹. Installation, alteration or repair of a manufactured home specifically requires a permit from the applicable local municipality¹⁰. The 2025 New York Uniform Code became fully effective on December 31, 2025, although the provisions prohibiting fossil-fuel equipment and building systems in new buildings remain suspended by court order and cannot currently be enforced⁸. A local code program may exempt listed minor work, including a qualifying one-story detached shed or playhouse no larger than 144 square feet, but exempt work must still comply with the codes². Permitted work is inspected during construction, and any permit-covered work requires a certificate of occupancy or compliance¹¹⁷.

Who issues building permits in Montgomery County, and how do you reach them?

There is no single county building department for Montgomery County parcels; each town, village or city administers building permits and code enforcement for its own land¹³. First identify the municipality containing the parcel, then ask its code-enforcement office. The Montgomery County Real Property Tax Service Agency provides parcel data, tax maps, tax rolls and assessment records that can help identify the municipality¹². As a concrete example, the Town of Mohawk Building and Code Enforcement office accepts applications to construct, alter, use or occupy a building or land and issues building permits to applicants who comply with the building codes¹³. The Mohawk contact applies only to land in that town; owners elsewhere should contact their own municipality³. Septic approval and driveway permits are separate from the building permit and are covered below.

Does Montgomery County have zoning?

Montgomery County does not have county-level zoning; zoning and code enforcement are handled by the town, village or city³. A parcel's permitted uses, setbacks, minimum lot size and accessory-building rules therefore need a municipal answer rather than a countywide one¹⁴. The Town of Mohawk shows how detailed that can get: its zoning law divides the town into districts and sets lot area, yards, coverage and height by district in a schedule¹⁵¹⁶. Mohawk's Zoning Enforcement office reviews residential zoning-use permit applications for compliance with town regulations, and applies only to Mohawk parcels¹⁷. We could not confirm district schedules for the county's other municipalities, so obtain the zoning map and dimensional table from the municipality before relying on a listing. Subdivision plats outside incorporated villages go through the town's local process where a town board has authorized planning-board review¹⁸.

How do septic permits work in Montgomery County?

We could not confirm which local or district health authority approves an ordinary residential septic system in Montgomery County, so ask the code-enforcement office for the parcel's municipality who must approve the design. New residential systems must meet New York's statewide Appendix 75-A standards, and an alternative system needs plan approval from the State or county health department official with jurisdiction before construction⁵¹⁹. New York does not require a state SPDES discharge permit when a system sends less than 1,000 gallons per day of sewage wastewater to groundwater and contains no industrial or other non-sewage waste, but that does not remove possible approval by a city health department, county health department or New York State Department of Health district office²⁰⁴. Only about 11% of Montgomery County soils are rated without severe limitations for a conventional drain field, so make a site evaluation an early contingency²¹.

Can you live in an RV or tiny home on your land in Montgomery County?

We could not confirm a countywide rule allowing or prohibiting occupancy of an RV or tiny home in Montgomery County, because the county does not administer zoning³. Municipal rules can be strict: in the Town of Mohawk, travel trailers are not permanent dwelling units, residency in a trailer camp is limited to 180 days a year, and occupancy outside a court or camp beyond 30 days needs a temporary certificate of occupancy from the Zoning Board of Appeals after inspection and a public hearing⁹. Mohawk also bars mobile homes from its R-2 Residential District and requires evidence of approved water and sewage systems with a mobile-home permit application²². Ask your own municipality whether the use is allowed and whether an RV may be occupied during construction. A tiny home used as a dwelling must also follow the building-permit process for work subject to the Uniform Code or Energy Code².

Building a home in Montgomery County: the steps, in order

1. Use the Montgomery County Real Property Tax Service Agency's parcel resources to confirm the parcel and its municipality before closing¹².
2. Get the municipal zoning map and dimensional rules, because Montgomery County does not administer zoning³.
3. Ask the municipality's code office which building permit, fees and construction documents apply; the application must at least describe the work, give the tax-map number and street address, and include construction documents²³¹³.
4. Ask the code office who approves the septic design, then make septic approval and a satisfactory site evaluation purchase contingencies⁴.
5. Ask the road owner whether a driveway permit is needed: a residence on a State highway needs a NYS Department of Transportation permit²⁴, and Montgomery County Public Works is the contact for county highways²⁵.
6. Keep work accessible for required inspections and obtain a certificate of occupancy or compliance for any permit-covered work¹¹⁷.

What to check before you buy land in Montgomery County

Soils are the first practical constraint: only about 11% of Montgomery County land is rated without severe limitations for a conventional septic drain field²¹. About 87% of county land has a slope of 15% or less, but a parcel-specific site evaluation is still necessary²⁶. If the parcel lies in a FEMA-mapped flood hazard area, private development needs a local floodplain development permit, usually handled by the building inspector or code enforcement official²⁷. Confirm whether frontage is on a town, county or state road before asking the road owner about driveway approval²⁵. Montgomery County's effective property-tax rate is about 2.6%, and the median annual property-tax bill is about $3,630, so verify the actual parcel record with Real Property Tax Service²⁸²⁹¹². Farmland value averages about $3,700 per acre, which is no substitute for parcel-specific comparable sales³⁰.

Watch-outs

• Building permits and zoning approval come from the municipality containing the parcel, while septic approval follows a separate health-authority track, so identify the town, village or city before applying¹³⁴.
• We could not confirm whether Montgomery County has an owner-builder exemption from licensed-contractor requirements; ask your town's building and code office directly⁶.
• Search results for "Montgomery County building department" can return other Montgomery Counties (Pennsylvania, Maryland, Ohio, Kansas, Texas and more); confirm you are on a montgomerycountyny.gov page or a Montgomery County, NY town's own site, such as the Town of Mohawk's, before calling a number¹³.

Sources

1. NYS Department of State - Building Standards and Codes (2026 county census)
2. Part 1203 Uniform Code and the Energy Code: Minimum Standards for Administration and Enforcement (New York statewide rule), quoted and re-checked
3. Montgomery County Frequently Asked Questions, quoted and re-checked
4. State Pollutant Discharge Elimination System (SPDES) Permit Program (New York statewide rule), quoted and re-checked
5. NYS Register March 18, 2015 Rule Making Activities — Part 75 authority and scope (New York statewide rule), quoted and re-checked
6. Consumer Alert: NYS Department of State’s Division of Consumer Protection Provides New Yorkers with Tips for Avoiding Home Improvement Scams (2026 county census)
7. Division of Building Standards and Codes Frequently Asked Questions, quoted and re-checked
8. Division of Building Standards and Codes Frequently Asked Questions, quoted and re-checked
9. Town of Mohawk Zoning Law, quoted and re-checked
10. Division of Building Standards and Codes Frequently Asked Questions, quoted and re-checked
11. Administration and Enforcement of the Uniform Code, quoted and re-checked
12. Montgomery County Real Property Tax Service Agency (montgomerycountyny.gov)
13. Town of Mohawk Building and Code Enforcement (townofmohawkny.com)
14. Montgomery County, NY Frequently Asked Questions, quoted and re-checked
15. Town of Mohawk Zoning Law, quoted and re-checked
16. Town of Mohawk Zoning Law, quoted and re-checked
17. Town of Mohawk Zoning Enforcement (townofmohawkny.com)
18. New York Town Law § 276: Subdivision review; approval of plats; development of filed plats (New York statewide rule), quoted and re-checked
19. NYS Register March 18, 2015 Rule Making Activities — Standards for Individual Onsite Water Supply and Individual Onsite Wastewater Treatment Systems (New York statewide rule), quoted and re-checked
20. State Pollutant Discharge Elimination System (SPDES) Permit Program (New York statewide rule), quoted and re-checked
21. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
22. Town of Mohawk Zoning Law, quoted and re-checked
23. Administration and Enforcement of the Uniform Code (New York statewide rule), quoted and re-checked
24. Residential Driveway Permits (New York statewide rule), quoted and re-checked
25. Montgomery County Department of Public Works (montgomerycountyny.gov)
26. Share of land at 15% slope or less: Bolthole Index county data
27. Floodplain Management - NYSDEC (New York statewide rule), quoted and re-checked
28. Effective property tax rate: Bolthole Index county data
29. Median property tax bill: Bolthole Index county data
30. Farmland value per acre (USDA census): Bolthole Index county data

Written October 9, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.