Day · ADU cost
What it costs to build an ADU in Day, NY
An 800 sq ft accessory dwelling unit in Day runs roughly $200k–260k, or about $249–327/sq ft, and that per-square-foot figure sits deliberately above the $204–268/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 Day maps 5 districts 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 Day
Standard finish, slab on grade, on a flat and clear part of the lot, general-contractor margin included. These are structure costs at Saratoga County pricing, before the service and septic work a second dwelling can trigger.
| Size | Type | $ / sq ft | Estimated total |
|---|---|---|---|
| 400 sq ft | Studio | $331–$433 | $130k–175k |
| 600 sq ft | One bedroom | $276–$362 | $165k–215k |
| 800 sq ft | One bedroom, larger | $249–$327 | $200k–260k |
| 1,000 sq ft | Two bedroom | $233–$305 | $235k–305k |
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–$11 | $7 | — |
| Foundation | $16–$23 | $16 | — |
| Framing | $25–$32 | $25 | — |
| Envelope - roof, siding, windows | $32–$41 | $32 | — |
| Plumbing | $28–$34 | $16 | 55% |
| Electrical | $18–$24 | $13 | 35% |
| HVAC | $23–$28 | $15 | 45% |
| Insulation | $7–$9 | $7 | — |
| Interior finishes | $32–$43 | $27 | 15% |
| Millwork & cabinetry | $18–$28 | $11 | 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 Day 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 |
|---|---|---|---|---|
| Lakefront Residential (the Great Sacandaga Lake shorefront district, and with Neighborhood Commercial the smallest lot in Town: 60,000 SQ FT — about 1.38 acres — with 150 ft of lot width, a 50 ft front yard, 20 ft side and 50 ft rear yards, 25% maximum building coverage and a 30 FT height cap. ACCESSORY STRUCTURES ARE CAUGHT BY THE SHORELINE SETBACK TOO ONCE THEY REACH 100 SQ FT: the general accessory setback is 15 ft in all zones, BUT accessory structures of 100 SQ FT OR LARGER are subject to the shoreline setbacks, and accessory structures OF ANY SIZE are subject to the same front yard setback as a principal building. A 10x10 shed is the threshold. THE TOWN ALSO SETS A MINIMUM FLOOR AREA OF 600 SQ FT for a dwelling in every district — a floor on what may be built, not a ceiling. Uses: a one-family dwelling is permitted by right; MULTI-FAMILY OR APARTMENT HOUSE IS NOT PERMITTED HERE AT ALL (it exists only in RMD and RLD, and only by site plan approval). Bed-and-breakfast, restaurant, tavern, marina/dockominium, commercial dock, campground, cemetery, club, day care, place of worship, roadside stand and lake-related recreation are all site-plan uses — the district is written to let a lakeshore business exist without letting it dominate. THE LOT MINIMA IN THE THREE LARGER DISTRICTS ARE THE APA LAND-USE INTENSITY GUIDELINES, NOT LOCAL NUMBERS: 3.2 ACRES (Moderate Intensity), 8.5 ACRES (Low Intensity) and 42 ACRES (Rural Use / Resource Management). Those figures recur across every Adirondack town and are the tell that a code has been written to the Park's intensity classes rather than to local judgment. They are one-unit-per-lot minima, so on a Rural/Resource parcel the effective density is roughly one dwelling per 42 acres.) | 1.38 ac | 50 / 20 / 50 ft | 30 ft | No |
| Neighborhood Commercial (small stores and service businesses serving the local population, on DIMENSIONS IDENTICAL TO LAKEFRONT RESIDENTIAL: 60,000 SQ FT, 150 ft of lot width, 50 ft front, 20 ft side, 50 ft rear, 25% coverage, 30 ft height, a 75 ft shoreline setback and a 50 ft stream setback. The two districts are dimensionally indistinguishable and are separated entirely by use. A ONE-FAMILY DWELLING IS PERMITTED BY RIGHT IN NC, but a MULTI-FAMILY OR APARTMENT HOUSE IS NOT PERMITTED HERE — it exists only in RMD and RLD. SENIOR CITIZEN HOUSING DEVELOPMENT and an ASSISTED LIVING FACILITY FOR SENIORS are site-plan uses in NC, RMD and RLD, which is the Town's only multi-unit residential path outside those two districts. Minimum dwelling floor area is 600 sq ft. § 4.5 requires a 30 FT GREEN SPACE BUFFER along side and rear lines for ANY NON-RESIDENTIAL USE bordering an existing residential property — defined as any lot of 10 acres or less whose principal use is residential with a lawfully existing principal structure — kept as vegetation, with no driveways, parking, storage or work area in it. The Planning Board may reduce the width at site plan approval without a variance. That buffer is the real constraint on a small commercial lot here. ) | 1.38 ac | 50 / 20 / 50 ft | 30 ft | No |
| Residential Moderate Density (rural residential neighbourhoods with moderate-size lots: a 3.2-ACRE minimum lot — the APA Moderate Intensity guideline — with 200 ft of lot width, a 75 ft front yard, 40 ft side and 50 ft rear yards, 25% coverage and 30 ft of height, plus a 75 ft stream setback and a 75 ft Great Sacandaga Lake shoreline setback. The district's purpose statement expressly encourages CONSOLIDATION OF VACANT UNDERSIZED LOTS to bring them into conformity — read with § 9.4, which lets any vacant nonconforming lot of record be built on for ONE single-family dwelling WITHOUT A VARIANCE provided it does not adjoin other lots in the same ownership (adjoining lots in one ownership are treated as a single lot) and provided it was also a vacant nonconforming lot of record as of MAY 22, 1973 or was created after that date in compliance with the Adirondack Park Agency Act. THAT 1973 DATE IS THE APA ACT'S OWN CUTOFF AND IT IS THE FIRST THING TO CHECK ON ANY UNDERSIZED DAY PARCEL. Agriculture is permitted by right; forestry is by right outside 528 ft of the South Shore Road centreline and by site plan within it. Minimum dwelling floor area 600 sq ft. THE LOT MINIMA IN THE THREE LARGER DISTRICTS ARE THE APA LAND-USE INTENSITY GUIDELINES, NOT LOCAL NUMBERS: 3.2 ACRES (Moderate Intensity), 8.5 ACRES (Low Intensity) and 42 ACRES (Rural Use / Resource Management). Those figures recur across every Adirondack town and are the tell that a code has been written to the Park's intensity classes rather than to local judgment. They are one-unit-per-lot minima, so on a Rural/Resource parcel the effective density is roughly one dwelling per 42 acres.) | 3.2 ac | 75 / 40 / 50 ft | 30 ft | No |
| Residential Low Density (rural residential neighbourhoods intended to retain a forested low-density character, with construction on steep slopes discouraged: an 8.5-ACRE minimum lot — the APA Low Intensity guideline — with 300 FT of lot width, a 75 ft front yard, a 50 ft side yard, a 50 ft rear yard, 25% coverage and 30 ft of height, plus a 75 ft stream setback. NO SHORELINE SETBACK IS STATED FOR RLD, RMD's and LR's 75 ft Great Sacandaga figure stopping at RMD — the district simply does not reach the lake. Like RMD it permits a MULTI-FAMILY DWELLING OR APARTMENT HOUSE by site plan approval — one of only two districts that do — along with senior citizen housing and assisted living. HUNTING OR FISHING CAMPS AND CABINS ARE PERMITTED BY RIGHT HERE (site plan in RMD, by right in RLD and RRC) and agriculture is by right. RLD is also the only district permitting an ADULT ENTERTAINMENT ESTABLISHMENT, by site plan. Junkyards, kennels, light industrial use, sawmills and mining are site-plan uses in RMD and RLD alike. Minimum dwelling floor area 600 sq ft; the 15 ft accessory setback applies, with any accessory structure held to the principal front yard setback regardless of size. THE LOT MINIMA IN THE THREE LARGER DISTRICTS ARE THE APA LAND-USE INTENSITY GUIDELINES, NOT LOCAL NUMBERS: 3.2 ACRES (Moderate Intensity), 8.5 ACRES (Low Intensity) and 42 ACRES (Rural Use / Resource Management). Those figures recur across every Adirondack town and are the tell that a code has been written to the Park's intensity classes rather than to local judgment. They are one-unit-per-lot minima, so on a Rural/Resource parcel the effective density is roughly one dwelling per 42 acres.) | 8.5 ac | 75 / 50 / 50 ft | 30 ft | No |
| MULTI-FAMILY, SENIOR HOUSING AND ASSISTED LIVING ARE ALL UNAVAILABLE HERE, as are bed-and-breakfasts, restaurants, taverns, retail and offices. What RRC does permit by right is agriculture, forestry and hunting or fishing camps and cabins; by site plan it allows campgrounds, clubs or lodges, golf courses, group camps, mining and quarrying, MOTOCROSS (the only district), sawmills, roadside stands, places of worship, telecommunication towers, tourist attractions, major and minor public utility structures and both lake-related and non-lake-related recreation. The 400 ft lot width carries an express exception for hunting and fishing camps, which is the one narrow path to a small parcel here. Minimum dwelling floor area 600 sq ft. THE LOT MINIMA IN THE THREE LARGER DISTRICTS ARE THE APA LAND-USE INTENSITY GUIDELINES, NOT LOCAL NUMBERS: 3.2 ACRES (Moderate Intensity), 8.5 ACRES (Low Intensity) and 42 ACRES (Rural Use / Resource Management). Those figures recur across every Adirondack town and are the tell that a code has been written to the Park's intensity classes rather than to local judgment. They are one-unit-per-lot minima, so on a Rural/Resource parcel the effective density is roughly one dwelling per 42 acres.) | 42 ac | 100 / 75 / 75 ft | 30 ft | No |
Size limits on record in Day
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 Day:
- Lakefront Residential (the Great Sacandaga Lake shorefront district, and with Neighborhood Commercial the smallest lot in Town: 60,000 SQ FT — about 1.38 acres — with 150 ft of lot width, a 50 ft front yard, 20 ft side and 50 ft rear yards, 25% maximum building coverage and a 30 FT height cap. ACCESSORY STRUCTURES ARE CAUGHT BY THE SHORELINE SETBACK TOO ONCE THEY REACH 100 SQ FT: the general accessory setback is 15 ft in all zones, BUT accessory structures of 100 SQ FT OR LARGER are subject to the shoreline setbacks, and accessory structures OF ANY SIZE are subject to the same front yard setback as a principal building. A 10x10 shed is the threshold. THE TOWN ALSO SETS A MINIMUM FLOOR AREA OF 600 SQ FT for a dwelling in every district — a floor on what may be built, not a ceiling. Uses: a one-family dwelling is permitted by right; MULTI-FAMILY OR APARTMENT HOUSE IS NOT PERMITTED HERE AT ALL (it exists only in RMD and RLD, and only by site plan approval). Bed-and-breakfast, restaurant, tavern, marina/dockominium, commercial dock, campground, cemetery, club, day care, place of worship, roadside stand and lake-related recreation are all site-plan uses — the district is written to let a lakeshore business exist without letting it dominate. THE LOT MINIMA IN THE THREE LARGER DISTRICTS ARE THE APA LAND-USE INTENSITY GUIDELINES, NOT LOCAL NUMBERS: 3.2 ACRES (Moderate Intensity), 8.5 ACRES (Low Intensity) and 42 ACRES (Rural Use / Resource Management). Those figures recur across every Adirondack town and are the tell that a code has been written to the Park's intensity classes rather than to local judgment. They are one-unit-per-lot minima, so on a Rural/Resource parcel the effective density is roughly one dwelling per 42 acres.)A 600 SQ FT MINIMUM dwelling floor area applies in every district, so a small unit is not automatically the easy option
- Neighborhood Commercial (small stores and service businesses serving the local population, on DIMENSIONS IDENTICAL TO LAKEFRONT RESIDENTIAL: 60,000 SQ FT, 150 ft of lot width, 50 ft front, 20 ft side, 50 ft rear, 25% coverage, 30 ft height, a 75 ft shoreline setback and a 50 ft stream setback. The two districts are dimensionally indistinguishable and are separated entirely by use. A ONE-FAMILY DWELLING IS PERMITTED BY RIGHT IN NC, but a MULTI-FAMILY OR APARTMENT HOUSE IS NOT PERMITTED HERE — it exists only in RMD and RLD. SENIOR CITIZEN HOUSING DEVELOPMENT and an ASSISTED LIVING FACILITY FOR SENIORS are site-plan uses in NC, RMD and RLD, which is the Town's only multi-unit residential path outside those two districts. Minimum dwelling floor area is 600 sq ft. § 4.5 requires a 30 FT GREEN SPACE BUFFER along side and rear lines for ANY NON-RESIDENTIAL USE bordering an existing residential property — defined as any lot of 10 acres or less whose principal use is residential with a lawfully existing principal structure — kept as vegetation, with no driveways, parking, storage or work area in it. The Planning Board may reduce the width at site plan approval without a variance. That buffer is the real constraint on a small commercial lot here. )A 600 SQ FT MINIMUM dwelling floor area applies in every district, so a small unit is not automatically the easy option
- Residential Moderate Density (rural residential neighbourhoods with moderate-size lots: a 3.2-ACRE minimum lot — the APA Moderate Intensity guideline — with 200 ft of lot width, a 75 ft front yard, 40 ft side and 50 ft rear yards, 25% coverage and 30 ft of height, plus a 75 ft stream setback and a 75 ft Great Sacandaga Lake shoreline setback. The district's purpose statement expressly encourages CONSOLIDATION OF VACANT UNDERSIZED LOTS to bring them into conformity — read with § 9.4, which lets any vacant nonconforming lot of record be built on for ONE single-family dwelling WITHOUT A VARIANCE provided it does not adjoin other lots in the same ownership (adjoining lots in one ownership are treated as a single lot) and provided it was also a vacant nonconforming lot of record as of MAY 22, 1973 or was created after that date in compliance with the Adirondack Park Agency Act. THAT 1973 DATE IS THE APA ACT'S OWN CUTOFF AND IT IS THE FIRST THING TO CHECK ON ANY UNDERSIZED DAY PARCEL. Agriculture is permitted by right; forestry is by right outside 528 ft of the South Shore Road centreline and by site plan within it. Minimum dwelling floor area 600 sq ft. THE LOT MINIMA IN THE THREE LARGER DISTRICTS ARE THE APA LAND-USE INTENSITY GUIDELINES, NOT LOCAL NUMBERS: 3.2 ACRES (Moderate Intensity), 8.5 ACRES (Low Intensity) and 42 ACRES (Rural Use / Resource Management). Those figures recur across every Adirondack town and are the tell that a code has been written to the Park's intensity classes rather than to local judgment. They are one-unit-per-lot minima, so on a Rural/Resource parcel the effective density is roughly one dwelling per 42 acres.)A 600 SQ FT MINIMUM dwelling floor area applies in every district, so a small unit is not automatically the easy option
- Residential Low Density (rural residential neighbourhoods intended to retain a forested low-density character, with construction on steep slopes discouraged: an 8.5-ACRE minimum lot — the APA Low Intensity guideline — with 300 FT of lot width, a 75 ft front yard, a 50 ft side yard, a 50 ft rear yard, 25% coverage and 30 ft of height, plus a 75 ft stream setback. NO SHORELINE SETBACK IS STATED FOR RLD, RMD's and LR's 75 ft Great Sacandaga figure stopping at RMD — the district simply does not reach the lake. Like RMD it permits a MULTI-FAMILY DWELLING OR APARTMENT HOUSE by site plan approval — one of only two districts that do — along with senior citizen housing and assisted living. HUNTING OR FISHING CAMPS AND CABINS ARE PERMITTED BY RIGHT HERE (site plan in RMD, by right in RLD and RRC) and agriculture is by right. RLD is also the only district permitting an ADULT ENTERTAINMENT ESTABLISHMENT, by site plan. Junkyards, kennels, light industrial use, sawmills and mining are site-plan uses in RMD and RLD alike. Minimum dwelling floor area 600 sq ft; the 15 ft accessory setback applies, with any accessory structure held to the principal front yard setback regardless of size. THE LOT MINIMA IN THE THREE LARGER DISTRICTS ARE THE APA LAND-USE INTENSITY GUIDELINES, NOT LOCAL NUMBERS: 3.2 ACRES (Moderate Intensity), 8.5 ACRES (Low Intensity) and 42 ACRES (Rural Use / Resource Management). Those figures recur across every Adirondack town and are the tell that a code has been written to the Park's intensity classes rather than to local judgment. They are one-unit-per-lot minima, so on a Rural/Resource parcel the effective density is roughly one dwelling per 42 acres.)A 600 SQ FT MINIMUM dwelling floor area applies in every district, so a small unit is not automatically the easy option
- MULTI-FAMILY, SENIOR HOUSING AND ASSISTED LIVING ARE ALL UNAVAILABLE HERE, as are bed-and-breakfasts, restaurants, taverns, retail and offices. What RRC does permit by right is agriculture, forestry and hunting or fishing camps and cabins; by site plan it allows campgrounds, clubs or lodges, golf courses, group camps, mining and quarrying, MOTOCROSS (the only district), sawmills, roadside stands, places of worship, telecommunication towers, tourist attractions, major and minor public utility structures and both lake-related and non-lake-related recreation. The 400 ft lot width carries an express exception for hunting and fishing camps, which is the one narrow path to a small parcel here. Minimum dwelling floor area 600 sq ft. THE LOT MINIMA IN THE THREE LARGER DISTRICTS ARE THE APA LAND-USE INTENSITY GUIDELINES, NOT LOCAL NUMBERS: 3.2 ACRES (Moderate Intensity), 8.5 ACRES (Low Intensity) and 42 ACRES (Rural Use / Resource Management). Those figures recur across every Adirondack town and are the tell that a code has been written to the Park's intensity classes rather than to local judgment. They are one-unit-per-lot minima, so on a Rural/Resource parcel the effective density is roughly one dwelling per 42 acres.)A 600 SQ FT MINIMUM dwelling floor area applies in every district, so a small unit is not automatically the easy option
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 National Grid territory. 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 rentalsNo local short-term-rental law on record - which is not the same as permission. NO SHORT-TERM-RENTAL PROVISION EXISTS IN THE TOWN OF DAY ZONING LAW. A full-text read of the 81-page law returns no 'short-term rental' and no 'vacation rental', and the Town's published list of local laws shows no rental enactment. Recorded 'unknown' rather than 'prohibited': whole-house rental of a permitted single-family dwelling is arguably the residential use itself, and absence of a found provision is NOT permission. WHAT IT DOES REGULATE IS THE OLDER TRANSIENT LADDER. BED AND BREAKFAST is a SITE PLAN use in LR, NC, RMD and RLD (not RRC), and § 8.20 confines it to NOT MORE THAN FIVE ROOMS offered for rent for transient occupancy, with meals — if offered at all — SERVED ONLY TO REGISTERED LODGERS. Appendix D defines it as 'a private dwelling in which at least one (1) and not more than five (5) rooms are offered for rent for transient occupancy'. TOURIST ACCOMMODATION is a separate site-plan use in NC, RMD and RLD, and a TOURIST ATTRACTION in RMD, RLD and RRC. CAMPGROUNDS AND RECREATIONAL VEHICLE PARKS are a site-plan use in every district under § 8.21 on a 10-ACRE minimum, at no more than 10 campsites per acre with a 2,500 sq ft minimum campsite, a 50 FT GREEN SPACE BUFFER around the whole facility, no campsite within 75 ft of the mean high water mark of any navigable water, and NYS Department of Health compliance. Parking is one space per guest sleeping room for a boarding home or tourist accommodation. Get a written answer from the Code Enforcement Officer at (518) 696-3789 before underwriting short-term rental income on a Sacandaga parcel. Separately, New York State has required every short-term-rental host to register the unit with the State through the county registry since 2025 regardless of what the municipality allows, and Saratoga County HAS adopted a county-level short-term-rental programme: a 3% occupancy tax and a MANDATORY county registry, covering any room or space in a dwelling let for under 30 consecutive days. Registration runs two years, an unregistered host faces fines of up to $500, and the booking platform is separately liable for processing an unregistered listing — so Airbnb and Vrbo will delist. The City of Saratoga Springs runs its own registry alongside it. Separate question from whether you can build the unit.
- Building dept(518) 696-3789
Sizing up a specific parcel in Day?
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 Day runs $204–268/sq ft, about $370k–480k at 1,800 sq ft , plus roughly $94,720 for a conforming lot. See what it costs to build a house in Day.
ADU cost in nearby towns
All Saratoga County towns: Mechanicville (City) · Saratoga Springs (City) · Ballston · Charlton · Clifton Park · Corinth · Edinburg · Galway · Greenfield · Halfmoon · Malta · Milton · Moreau · Northumberland · Providence · Saratoga · Stillwater · Waterford · Wilton · Ballston Spa (Village) · Corinth (Village) · Round Lake (Village) · Schuylerville (Village) · South Glens Falls (Village) · Stillwater (Village) · Victory (Village) · Waterford (Village)
More on Day: Can you build an ADU here? · Zoning for new construction · Saratoga County build cost
ADU cost in Day: common questions
How much does it cost to build an ADU in Day, NY?
An 800 sq ft accessory dwelling unit in Town of Day runs roughly $200k–260k at a standard finish, general-contractor margin included. A 400 sq ft studio runs about $130k–175k. 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 Day?
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 $249–327/sq ft against $204–268/sq ft for a full house, even though it is the same trades doing the same work.
Are ADUs allowed in Day?
Town of Day has 5 districts. All districts prohibit ADUs. Check the specific address with the free ADU checker or confirm with the building department at (518) 696-3789 before you spend money on design.
Can I rent an ADU in Day short term?
No local short-term-rental law on record - which is not the same as permission for Town of Day. 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 Saratoga 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 Day vary by district and often carry exceptions this page does not show; zoning last reviewed 2026-08-03; verify with the building department at (518) 696-3789 before relying on any answer. Sources: Offsite / Aldo cost engine (costEngine.js + constants.js); zoning dataset (municipalData.js).