ADU · Sullivan County

Can you build an ADU in Fremont, NY?

Town of Fremont has 8 districts. ADU data not yet available - verify with the building department at (845) 887-6605. Check your address to confirm the district that applies to your parcel:

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What the Fremont code says

Fremont's code has no accessory dwelling unit, accessory apartment, in-law apartment or guest cottage category, and § 100.14(E) prohibits any use not specifically listed on the Schedule of District Regulations. No district lists a second dwelling unit as an accessory use.

Conditions the code attaches:

The Planning Board may find an unlisted use similar to a listed one, but it can then proceed only as a special use, and not if that use is already permitted in another district (§ 100.14(E)).
Where a two-family dwelling is a principal permitted use, the minimum lot area applies to each dwelling unit, so a second unit requires twice the minimum lot area (§ 100.15(A)).
Customary residential accessory uses at § 100.13 cover garden houses, playhouses, tool sheds, greenhouses, pools, private garages, pets and crops, with no habitable unit.
Hunting and fishing cabins are permitted for single-family purposes only.
Confirm the current standards with the building department at (845) 887-6605 before counting on a second unit.

What the Fremont code indicates by district

The table below shows how each district treats ADUs, alongside the lot and setback standards that govern a second unit. District boundaries and conditions vary, so treat this as a starting point and confirm the district that applies to your parcel.

District	Min lot	Setbacks F / S / R	Max height	ADU
Residential Recreation District	0.92 ac	60 / 25 / 50 ft	40 ft	—
Residential District	0.92 ac	60 / 25 / 50 ft	40 ft	—
Hamlet District	0.69 ac	50 / 25 / 40 ft	40 ft	—
River Conservation District	2.75 ac	60 / 50 / 50 ft	40 ft	—
Mountain Conservation District (Basket Sub-District)	4.59 ac	60 / 50 / 50 ft	40 ft	—
Mountain Conservation District (Plateau Sub-District)	2.75 ac	60 / 50 / 50 ft	40 ft	—
Anawanda Lake Conservation District	2.75 ac	60 / 50 / 50 ft	35 ft	—
Muskoday-Tennanah Lake Conservation District	4.59 ac	60 / 50 / 50 ft	35 ft	—

Residential Recreation District - On an on-site well and septic system at a slope of 0 to 8% the minimum lot is 40,000 square feet, 150 feet wide and 150 feet deep, with a 60 foot front yard, 25 foot side yards, 60 feet for both sides, a 50 foot rear yard, 15% lot coverage and a 40 foot height limit.

Slope sets the lot minimum here: 80,000 square feet at a slope of 8 to 15%, 120,000 square feet at 15 to 25%, and 200,000 square feet at 25% and above.
The minimum lot area rises by 40,000 square feet where a seasonal high water table or bedrock lies 4 feet or less down, and by 80,000 square feet where either lies less than 2 feet down.
On central sewage and water the minimum lot is 30,000 square feet, 125 feet wide and 125 feet deep, with a 50 foot front yard, 50 feet for both sides, a 40 foot rear yard and 25% lot coverage.
A conservation subdivision is granted by the Planning Board with the plat, not by right. Yards drop to 35 feet front and 20 side and rear, on 40,000 square feet on-site or 20,000 on central.
A two-family dwelling requires twice the minimum lot area, and a yard bordering a lake, stream or other water body is at least 100 feet deep.
Every residential lot needs a front lot line at least 50 feet long. An unattached accessory structure sits 5 feet from a side or rear lot line, or 10 feet for a garage absent special use approval.

Residential District - On an on-site well and septic system the minimum lot is 40,000 square feet, 150 feet wide and 150 feet deep, with a 60 foot front yard, 25 foot side yards, 60 feet for both sides, a 50 foot rear yard, 25% lot coverage and a 40 foot height limit.

On central sewage and water the minimum lot is 30,000 square feet, 125 feet wide and 125 feet deep, with a 50 foot front yard, 50 feet for both sides and a 40 foot rear yard.
A conservation subdivision is granted by the Planning Board with the plat, not by right. Yards drop to 35 feet front and 20 side and rear, on 40,000 square feet on-site or 20,000 on central.
A two-family dwelling requires twice the minimum lot area, and a yard bordering a lake, stream or other water body is at least 100 feet deep.
Every residential lot needs a front lot line at least 50 feet long. An unattached accessory structure sits 5 feet from a side or rear lot line, or 10 feet for a garage absent special use approval.

Hamlet District - On an on-site well and septic system the minimum lot is 30,000 square feet, 125 feet wide and 125 feet deep, with a 50 foot front yard, 25 foot side yards, 50 feet for both sides, a 40 foot rear yard, 15% lot coverage and a 40 foot height limit.

On central sewage with an on-site well the minimum lot is 20,000 square feet, 100 feet wide and 100 feet deep, with a 40 foot front yard, 20 foot side and rear yards and 25% lot coverage.
On central sewage and water the minimum lot is 12,000 square feet, 100 feet wide and 100 feet deep, with a 40 foot front yard, 20 foot side and rear yards and 25% lot coverage.
A conservation subdivision is granted by the Planning Board with the plat, not by right. Yards drop to 35 feet front and 20 side and rear, on 40,000 square feet on-site or 20,000 on central.
That 40,000 square foot cluster floor is larger than the 30,000 square foot minimum this district sets, so cluster design lowers the lot minimum here only on central sewer and water.
On a Tennanah Lake parcel with shoreline frontage, impervious surfaces in the waterfront yard may not exceed 15% of that yard, and the waterfront yard is at least 100 feet deep.
Every residential lot needs a front lot line at least 50 feet long. An unattached accessory structure sits 5 feet from a side or rear lot line, or 10 feet for a garage absent special use approval.

River Conservation District - The minimum lot is 120,000 square feet whatever the water and sewage service, 150 feet wide and 150 feet deep, with a 60 foot front yard, 50 foot side yards, 100 feet for both sides, a 50 foot rear yard, 10% lot coverage and a 40 foot height limit.

The town's conservation subdivision option does not reach this district, so lots here cannot be clustered on smaller parcels.
A two-family dwelling requires twice the minimum lot area, and a yard bordering a lake, stream or other water body is at least 100 feet deep.
Every residential lot needs a front lot line at least 50 feet long. An unattached accessory structure sits 5 feet from a side or rear lot line, or 10 feet for a garage absent special use approval.

Mountain Conservation District (Basket Sub-District) - The minimum lot is 200,000 square feet whatever the water and sewage service, 200 feet wide and 200 feet deep, with a 60 foot front yard, 50 foot side yards, 100 feet for both sides, a 50 foot rear yard, 5% lot coverage and a 40 foot height limit.

A conservation subdivision is granted by the Planning Board with the plat, not by right. Yards drop to 35 feet front and 20 side and rear, on 40,000 square feet on-site or 20,000 on central.
A two-family dwelling requires twice the minimum lot area, and a yard bordering a lake, stream or other water body is at least 100 feet deep.
Every residential lot needs a front lot line at least 50 feet long. An unattached accessory structure sits 5 feet from a side or rear lot line, or 10 feet for a garage absent special use approval.

Mountain Conservation District (Plateau Sub-District) - The minimum lot is 120,000 square feet whatever the water and sewage service, 150 feet wide and 150 feet deep, with a 60 foot front yard, 50 foot side yards, 100 feet for both sides, a 50 foot rear yard, 5% lot coverage and a 40 foot height limit.

A conservation subdivision is granted by the Planning Board with the plat, not by right. Yards drop to 35 feet front and 20 side and rear, on 40,000 square feet on-site or 20,000 on central.
A two-family dwelling requires twice the minimum lot area, and a yard bordering a lake, stream or other water body is at least 100 feet deep.
Every residential lot needs a front lot line at least 50 feet long. An unattached accessory structure sits 5 feet from a side or rear lot line, or 10 feet for a garage absent special use approval.

Anawanda Lake Conservation District - The minimum lot is 120,000 square feet whatever the water and sewage service, 200 feet wide and 200 feet deep, with a 60 foot front yard, 50 foot side yards, 100 feet for both sides, a 50 foot rear yard and a 35 foot height limit.

Coverage is capped as an area rather than a percentage: 6,000 square feet on a lot under 1 acre, 7,500 square feet on 1 to 2 acres and 9,000 square feet on 2 to 5 acres.
The same coverage cap is 10,000 square feet on 5 to 10 acres and 15,000 square feet on 10 acres and above.
A conservation subdivision is granted by the Planning Board with the plat, not by right. Yards drop to 35 feet front and 20 side and rear, on 40,000 square feet on-site or 20,000 on central.
Impervious surfaces inside a waterfront yard may not exceed 15% of that yard, and a yard bordering a lake, stream or other water body is at least 100 feet deep.
A two-family dwelling requires twice the minimum lot area.
Every residential lot needs a front lot line at least 50 feet long. An unattached accessory structure sits 5 feet from a side or rear lot line, or 10 feet for a garage absent special use approval.

Muskoday-Tennanah Lake Conservation District - The minimum lot is 200,000 square feet whatever the water and sewage service, 200 feet wide and 200 feet deep, with a 60 foot front yard, 50 foot side yards, 100 feet for both sides, a 50 foot rear yard and a 35 foot height limit.

Coverage is capped as an area rather than a percentage: 6,000 square feet on a lot under 1 acre, 7,500 square feet on 1 to 2 acres and 9,000 square feet on 2 to 5 acres.
The same coverage cap is 10,000 square feet on 5 to 10 acres and 15,000 square feet on 10 acres and above.
A conservation subdivision is granted by the Planning Board with the plat, not by right. Yards drop to 35 feet front and 20 side and rear, on 40,000 square feet on-site or 20,000 on central.
Impervious surfaces inside a waterfront yard may not exceed 15% of that yard, and a yard bordering a lake, stream or other water body is at least 100 feet deep.
A two-family dwelling requires twice the minimum lot area.
Every residential lot needs a front lot line at least 50 feet long. An unattached accessory structure sits 5 feet from a side or rear lot line, or 10 feet for a garage absent special use approval.

ADUs vs. short-term rentals in Fremont

No local short-term-rental law on record - which is not the same as permission for Town of Fremont. Fremont has not adopted a local short term rental permitting law, so no local permit requirement is confirmed for this parcel. Since no local rule is on the books, confirm with the building department before counting on renting short term. These are separate questions from whether you can build an ADU — a unit you're allowed to add isn't automatically one you're allowed to rent nightly, so check both.

Good to know

Residential lot minimum0.69–0.92 ac — an ADU still has to fit the district's lot and setback envelope.
UtilityNYSEG territory.
Zoning codefremontny.org/Section%20100%20Town%20Zoning%20Law%20(2016).pdf
Building dept(845) 887-6605

ADU FAQ — Fremont, NY

Are ADUs allowed in Fremont, NY?

Town of Fremont has 8 districts. ADU data not yet available - verify with the building department at (845) 887-6605. Check your address with the free ADU checker.

Do I need a special permit for an ADU in Fremont?

ADU data not yet available for Town of Fremont - verify with the building department at (845) 887-6605.

Can I use an ADU as a short-term rental in Fremont?

No local short-term-rental law on record - which is not the same as permission for Town of Fremont. ADU occupancy and short-term-rental rules are separate: an ADU you can build isn't automatically one you can rent nightly. Confirm both before you count on STR income.

Run the free ADU check for your parcel →

What an ADU costs to build in Fremont

Permission is one question and budget is another. An 800 sq ft accessory unit here runs roughly $190k–250k at a standard finish, and the per-square-foot rate comes in above a full house because the kitchen, bath, panel and heating plant cost the same either way. See the full cost to build an ADU in Fremont, priced by size.

How we know this

Sections analyzed: Zoning Law Section 100 (2016) § 100.10 districts; § 100.13 definitions; § 100.14(E) unlisted uses; § 100.15(A); Appendix 2 Schedule of District Regulations
Last reviewed: 2026-10-07
Not covered here: Overlay districts, the zoning map, and any conditions attached to an individual parcel. Size limits and owner-occupancy terms sit in the code section above, not in this summary.

More on Fremont: Full zoning for new construction · ADU build cost · House build cost · ADU rules across Sullivan County · All Sullivan County towns

ADU information for Town of Fremont is compiled from the municipal code (last reviewed 2026-10-07) and provided for decision-support only — not legal or architectural advice. ADU eligibility, size, owner-occupancy and permit conditions vary by district and often carry exceptions; verify with the building department at (845) 887-6605 before relying on any answer. Source: the Offsite / Aldo zoning dataset.