Andes · ADU cost
What it costs to build an ADU in Andes, NY
An 800 sq ft accessory dwelling unit in Andes runs roughly $185k–245k, or about $233–305/sq ft, and that per-square-foot figure sits deliberately above the $191–250/sq ft a full house costs here. An ADU still needs one whole kitchen, one whole bath, its own service panel and its own heating plant no matter how small you draw it, and those costs do not shrink with the floor plan, so they land on half the square footage and push the rate up. Whether the town will let you build one is a separate question from what it costs, and it gets answered parcel by parcel rather than townwide, since the Town of Andes maps 1 district that treat accessory units differently from one another, so read the table below as a starting point rather than a verdict.
ADU cost by size in Andes
Standard finish, slab on grade, on a flat and clear part of the lot, general-contractor margin included. These are structure costs at Delaware County pricing, before the service and septic work a second dwelling can trigger.
| Size | Type | $ / sq ft | Estimated total |
|---|---|---|---|
| 400 sq ft | Studio | $309–$404 | $125k–160k |
| 600 sq ft | One bedroom | $258–$338 | $155k–205k |
| 800 sq ft | One bedroom, larger | $233–$305 | $185k–245k |
| 1,000 sq ft | Two bedroom | $218–$285 | $220k–285k |
400 sq ft — One room plus a bath. Garage conversions and small backyard cottages land here.
600 sq ft — The most common detached build - a real bedroom, full kitchen, one bath.
800 sq ft — Room for a proper living area. Still a single bath and one kitchen.
1,000 sq ft — About as large as most codes allow an accessory unit to go.
Why the rate is higher than a house
The systems below are priced for an 800 sq ft unit. The middle column is what each system would cost if it simply shrank with the floor plan; the left column is what it actually costs once you account for the equipment a dwelling needs one of regardless of size. The gap between the two columns is the whole reason small builds price the way they do.
| System | $ / sq ft in an ADU | If it scaled with floor area | Fixed per unit |
|---|---|---|---|
| Site work | $7–$10 | $7 | — |
| Foundation | $15–$21 | $15 | — |
| Framing | $24–$30 | $24 | — |
| Envelope - roof, siding, windows | $30–$38 | $30 | — |
| Plumbing | $26–$32 | $15 | 55% |
| Electrical | $17–$22 | $12 | 35% |
| HVAC | $21–$27 | $14 | 45% |
| Insulation | $7–$9 | $7 | — |
| Interior finishes | $30–$40 | $26 | 15% |
| Millwork & cabinetry | $17–$26 | $10 | 55% |
The fixed-per-unit share is a modeling assumption, not a figure from the code: it is our estimate of how much of each system's budget buys equipment a dwelling needs exactly one of - a kitchen rough-in, a bath group, a service panel, a heating plant - and therefore does not shrink when the unit does. Site work, foundation, framing, envelope and insulation are treated as scaling straight with floor area, which understates the premium slightly, because a small building carries more envelope per square foot of floor than a large one.
What the Andes code says about accessory units
Whether you can build one, and how large, is decided by the district your parcel sits in rather than by the town as a whole. The table shows how each mapped district treats ADUs alongside the lot and setback standards a second unit still has to fit inside. District boundaries and conditions vary, so treat it as a starting point and confirm the district that applies to your parcel.
| District | Min lot | Setbacks F / S / R | Max height | ADU |
|---|---|---|---|---|
| General Rural District — THE ONLY ZONING DISTRICT IN THE TOWN. Andes does not divide itself into districts: Article 2 establishes a single General Rural District and § 2.02 applies it to all land in the Town, so for any Andes parcel this row IS the answer and there is no map lookup to do. Minimum lot size one acre for any lot created after the law took effect. NO HEIGHT LIMIT AND NO LOT COVERAGE LIMIT ARE STATED ANYWHERE IN THE LAW — both nulls are a correct reading and must not be 'fixed' by borrowing a neighbouring town's figures. The only height figure in the document, 24 feet, is one of the thresholds that disqualifies an activity from counting as a home business under § 2.10; it is not a cap on building height. Minimum frontage is 100 feet for lots under 3 acres, 200 feet for lots of 3 to 5 acres and 300 feet for lots over 5 acres, with a reduced cul-de-sac alternative of 60, 70 and 80 feet respectively. Side and rear setbacks are 25 feet for lots under 3 acres, 50 feet for lots of 3 to 5 acres and 75 feet for lots over 5 acres — so buying more land tightens the yards rather than loosening them, and a 6-acre parcel needs 300 feet of frontage and 75-foot side yards. Driveways, fences, walls and hedges are exempt from the setbacks under § 2.06(E). § 2.06(C) reads 75 feet from the center line of a road whose right-of-way is less than 60 feet, OR 45 feet from the edge of the right-of-way where the right-of-way is 60 feet or more. ON A NARROWER RIGHT-OF-WAY THE CENTERLINE RULE BINDS HARDER — a 33-foot right-of-way pushes the building about 58.5 feet back — and on a right-of-way of 60 feet or more the second rule governs instead and the setback drops to 45 feet from the edge. Check the actual right-of-way width before siting. Each tract is allocated a maximum number of dwelling units: 1 under 5 acres, 2 from 5 to 9.99 acres, and 3 at 10 acres and over plus one additional unit for each additional 7 acres over 10. A 100-acre tract is therefore allocated 3 + 12 = 15 dwelling units, where sizing from the one-acre minimum lot alone would suggest something near 100 — an overstatement of roughly six to seven times. TRACT IS A FROZEN TERM AND THIS IS THE PART THAT CATCHES PEOPLE: Article 12 defines a Tract of Land as a parcel for which a separate designation existed on the Delaware County Real Property Identification Maps AS OF THE DATE THE LAW WAS ADOPTED, so the allocation attaches to the 1993 parcel and subdividing does not create new units. Allocation already consumed by dwellings built or lots split since 1993 comes off the total, and § 2.05 requires subdivision plats approved after adoption to note the units allocated to each lot and the subdivider to give every grantee a sworn affidavit of that allocation — so on any parcel with post-1993 history the remaining allocation is a document to obtain, not a number to compute. § 2.04 adds that site conditions such as topography or soil limitations may reduce the achievable count below the allocated maximum. USES: single-family dwellings, two-family dwellings, accessory apartments, home businesses, agricultural buildings and customary accessory structures are permitted on a zoning permit from the Code Enforcement Officer; agriculture, timber management and harvesting and customary accessory uses need no permit at all. Multiple dwellings, commercial buildings and activities, industrial buildings and activities, mobile homes, and exterior additions enlarging an existing commercial, industrial or multiple-dwelling structure by more than a cumulative 25% all require a special use permit AND site plan approval from the Planning Board. All new housing units, including modular and mobile homes and individual units in a multiple dwelling, must have at least 500 square feet of floor area under § 3.03. | 1 ac | 50 / 25 / 25 ft | — | As of right |
Size limits on record in Andes
Where the code states a size cap, it decides which row of the cost table above actually applies to you. These are the caps recorded for Andes:
- General Rural District — THE ONLY ZONING DISTRICT IN THE TOWN. Andes does not divide itself into districts: Article 2 establishes a single General Rural District and § 2.02 applies it to all land in the Town, so for any Andes parcel this row IS the answer and there is no map lookup to do. Minimum lot size one acre for any lot created after the law took effect. NO HEIGHT LIMIT AND NO LOT COVERAGE LIMIT ARE STATED ANYWHERE IN THE LAW — both nulls are a correct reading and must not be 'fixed' by borrowing a neighbouring town's figures. The only height figure in the document, 24 feet, is one of the thresholds that disqualifies an activity from counting as a home business under § 2.10; it is not a cap on building height. Minimum frontage is 100 feet for lots under 3 acres, 200 feet for lots of 3 to 5 acres and 300 feet for lots over 5 acres, with a reduced cul-de-sac alternative of 60, 70 and 80 feet respectively. Side and rear setbacks are 25 feet for lots under 3 acres, 50 feet for lots of 3 to 5 acres and 75 feet for lots over 5 acres — so buying more land tightens the yards rather than loosening them, and a 6-acre parcel needs 300 feet of frontage and 75-foot side yards. Driveways, fences, walls and hedges are exempt from the setbacks under § 2.06(E). § 2.06(C) reads 75 feet from the center line of a road whose right-of-way is less than 60 feet, OR 45 feet from the edge of the right-of-way where the right-of-way is 60 feet or more. ON A NARROWER RIGHT-OF-WAY THE CENTERLINE RULE BINDS HARDER — a 33-foot right-of-way pushes the building about 58.5 feet back — and on a right-of-way of 60 feet or more the second rule governs instead and the setback drops to 45 feet from the edge. Check the actual right-of-way width before siting. Each tract is allocated a maximum number of dwelling units: 1 under 5 acres, 2 from 5 to 9.99 acres, and 3 at 10 acres and over plus one additional unit for each additional 7 acres over 10. A 100-acre tract is therefore allocated 3 + 12 = 15 dwelling units, where sizing from the one-acre minimum lot alone would suggest something near 100 — an overstatement of roughly six to seven times. TRACT IS A FROZEN TERM AND THIS IS THE PART THAT CATCHES PEOPLE: Article 12 defines a Tract of Land as a parcel for which a separate designation existed on the Delaware County Real Property Identification Maps AS OF THE DATE THE LAW WAS ADOPTED, so the allocation attaches to the 1993 parcel and subdividing does not create new units. Allocation already consumed by dwellings built or lots split since 1993 comes off the total, and § 2.05 requires subdivision plats approved after adoption to note the units allocated to each lot and the subdivider to give every grantee a sworn affidavit of that allocation — so on any parcel with post-1993 history the remaining allocation is a document to obtain, not a number to compute. § 2.04 adds that site conditions such as topography or soil limitations may reduce the achievable count below the allocated maximum. USES: single-family dwellings, two-family dwellings, accessory apartments, home businesses, agricultural buildings and customary accessory structures are permitted on a zoning permit from the Code Enforcement Officer; agriculture, timber management and harvesting and customary accessory uses need no permit at all. Multiple dwellings, commercial buildings and activities, industrial buildings and activities, mobile homes, and exterior additions enlarging an existing commercial, industrial or multiple-dwelling structure by more than a cumulative 25% all require a special use permit AND site plan approval from the Planning Board. All new housing units, including modular and mobile homes and individual units in a multiple dwelling, must have at least 500 square feet of floor area under § 3.03.§ 3.03 sets a floor of 500 square feet of floor area for ALL new housing units, which applies to a second unit as much as a first
Costs an ADU adds that a house does not
- Septic and water A second dwelling adds bedrooms to the design flow, which on an unsewered parcel often means expanding or replacing the existing system rather than tapping it. This is the single most common reason an ADU budget moves after design, and it is site-specific enough that no model should quote it - get it evaluated early.
- Utility service A detached unit needs power run to it, and whether it goes on its own meter or subfeeds the main house changes both the cost and the permit path.
- Access and parking Many codes require an added parking space for the accessory unit, and a detached unit usually needs a driveway extension or a path, both of which count against a lot-coverage or impervious-surface cap.
- Short-term rentalsShort-term rentals allowed with local rules. Short-term rentals are REGULATED, but not by the zoning law — Local Law 1 of 2022 is a standalone transient-rental permit regime and the 1993 Zoning Law contains no transient, tourist-home or bed-and-breakfast provision at all. A search of the zoning law for short-term rental language returns nothing, and reading that silence as permission would be wrong: the Town created a separate instrument instead. Under Local Law 1 of 2022 anyone operating a transient rental must hold a permit filed with the Town, obtained from the Code Enforcement Officer. Enforcement is active and specific rather than nominal — the Town's own enforcement letter tells operators it has identified them as operating a transient rental, gives 30 days to apply, and warns that without a filed permit the operation may be discontinued and occupants removed from the premises. Penalties escalate: $350 for a first offence, $350–$700 for a second, $700–$1,000 for a third and subsequent offences, and up to six months in jail. The full text of Local Law 1 of 2022 was not located online — only the application form and enforcement letter are published — so confirm the operating terms with the Code Enforcement Officer before underwriting rental income. Because the permit is administered by the Code Enforcement Officer rather than through site plan review, a transient rental here does not appear to trigger the Planning Board, which is a materially lighter path than the neighbouring Village of Margaretville's regime that Andes' own Planning Board discussed and deliberately declined to copy. Separate question from whether you can build the unit.
Sizing up a specific parcel in Andes?
Aldo pulls the exact zoning district, setbacks, and build feasibility for any parcel — before you buy. Enter your email to open Aldo and run your free report.
Building a full house instead?
A standard-finish house in Andes runs $191–250/sq ft, about $345k–450k at 1,800 sq ft . See what it costs to build a house in Andes.
ADU cost in nearby towns
All Delaware County towns: Delhi · Franklin · Middletown · Sidney · Walton · Delhi (Village) · Hancock (Village) · Sidney (Village) · Walton (Village)
More on Andes: Can you build an ADU here? · Zoning for new construction · Delaware County build cost
ADU cost in Andes: common questions
How much does it cost to build an ADU in Andes, NY?
An 800 sq ft accessory dwelling unit in Town of Andes runs roughly $185k–245k at a standard finish, general-contractor margin included. A 400 sq ft studio runs about $125k–160k. Those are structure costs on an easy site and do not include the septic, water or electrical service work a second unit often triggers.
Why does an ADU cost more per square foot than a house in Andes?
Because a lot of a dwelling's cost is per dwelling, not per square foot. One kitchen, one bath group, one service panel and one heating plant cost about the same in an 800 sq ft cottage as in a 1,800 sq ft house, so on the smaller unit they get spread over less than half the floor area. That is why an ADU here prices at $233–305/sq ft against $191–250/sq ft for a full house, even though it is the same trades doing the same work.
Are ADUs allowed in Andes?
Town of Andes has 1 district. The only district allows ADUs. Check the specific address with the free ADU checker or confirm with the building department before you spend money on design.
Can I rent an ADU in Andes short term?
Short-term rentals allowed with local rules for Town of Andes. ADU rules and short-term-rental rules are set separately, so a unit you are allowed to build is not automatically one you are allowed to rent nightly. Confirm both before you underwrite the build on short-term-rental income.
ADU costs are modeled estimates in current 2026 dollars at the Delaware County regional index, general-contractor margin included, derived from Offsite's cost engine with a stated adjustment for the equipment a dwelling needs one of regardless of size. They are planning numbers for decision-support only - not a bid, quote, or guarantee, and not legal, architectural or engineering advice. They cover the structure and exclude septic expansion, utility service runs, site work beyond a flat and clear pad, and permit fees. ADU eligibility, size, owner-occupancy and permit conditions in the Town of Andes vary by district and often carry exceptions this page does not show; zoning last reviewed 2026-08-24; verify with the municipality before relying on any answer. Sources: Offsite / Aldo cost engine (costEngine.js + constants.js); zoning dataset (municipalData.js).