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.
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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 | 1.38 ac | 50 / 20 / 50 ft | 30 ft | No |
| Neighborhood Commercial | 1.38 ac | 50 / 20 / 50 ft | 30 ft | No |
| Residential Moderate Density | 3.2 ac | 75 / 40 / 50 ft | 30 ft | No |
| Residential Low Density | 8.5 ac | 75 / 50 / 50 ft | 30 ft | No |
| Residential/Resource Conservation | 42 ac | 100 / 75 / 75 ft | 30 ft | No |
Lakefront Residential - The binding line on a lakefront parcel is the 75 ft shoreline setback from the mean high water mark of Great Sacandaga Lake, with a 50 ft stream setback from the mean high water mark of any navigable lake, pond or stream.
- An existing structure inside the shoreline setback area may not be expanded within it.
- Accessory structures take a 15 ft setback, but one of 100 sq ft or larger is subject to the shoreline setbacks, and one of any size takes the same front yard as a principal building.
- A fence counts as a structure, so the shoreline setback reaches it; boundary and perimeter fences up to 6 ft may stand inside the setback area except in shoreline areas, where § 8.2C governs.
- A small lot separately owned when the law passed may be built on without a variance, with side yards reduced in proportion to the width shortfall, if it adjoins no other property the applicant owns.
- The front yard may instead equal the average depth of the buildings within 100 ft on either or both sides, subject to a floor of 40 ft and never more than the district requires.
- The rear yard is reduced in proportion on a lot that was already under the district minimum when the law passed.
Neighborhood Commercial - The dimensions here are identical to the lakefront district's and the two are separated entirely by use. A one-family dwelling is permitted by right, but a multi-family or apartment house is not available in NC: it exists only in RMD and RLD.
- A 75 ft Great Sacandaga shoreline setback and a 50 ft stream setback run beside the yards.
- Senior citizen housing and an assisted living facility for seniors are site plan uses here, which is the Town's only multi-unit residential path outside RMD and RLD.
- Accessory structures take a 15 ft setback, but one of 100 sq ft or larger is subject to the shoreline setbacks, and one of any size takes the same front yard as a principal building.
- A small lot separately owned when the law passed may be built on without a variance, with side yards reduced in proportion to the width shortfall, if it adjoins no other property the applicant owns.
- The front yard may instead equal the average depth of the buildings within 100 ft on either or both sides, subject to a floor of 40 ft and never more than the district requires.
- Retail fuel sales, a laundromat, a shopping centre and a hospital are available here and nowhere else in the town, each by site plan approval.
Residential Moderate Density - A multi-family dwelling or apartment house is available here by site plan approval, in one of only two districts where it is available at all, and no separate dimensional standard is published for it: the district figures govern and unit count is settled in site plan review.
- A 75 ft stream setback and a 75 ft Great Sacandaga shoreline setback run beside the yards.
- Senior citizen housing and assisted living are site plan uses here as well.
- Accessory structures take a 15 ft setback, but one of 100 sq ft or larger is subject to the shoreline setbacks, and one of any size takes the same front yard as a principal building.
- A small lot separately owned when the law passed may be built on without a variance, with side yards reduced in proportion to the width shortfall, if it adjoins no other property the applicant owns.
- The front yard may instead equal the average depth of the buildings within 100 ft on either or both sides, subject to a floor of 40 ft and never more than the district requires.
- The purpose of the district expressly encourages consolidating vacant undersized lots to bring them into conformity.
Residential Low Density - A 75 ft stream setback runs beside the yards here. No shoreline setback is stated for RLD, because the district does not reach the lake. A multi-family dwelling or apartment house is available by site plan approval, in one of only two districts where it is.
- Hunting or fishing camps and cabins are permitted by right here, where RMD requires site plan approval, and agriculture is by right.
- Senior citizen housing and assisted living are site plan uses here as well; an adult entertainment establishment is available in RLD alone, by site plan.
- Junkyards, kennels, light industrial use, sawmills and mining are site plan uses in RMD and RLD alike.
- Accessory structures take a 15 ft setback, but one of 100 sq ft or larger is subject to the shoreline setbacks, and one of any size takes the same front yard as a principal building.
- A small lot separately owned when the law passed may be built on without a variance, with side yards reduced in proportion to the width shortfall, if it adjoins no other property the applicant owns.
- The front yard may instead equal the average depth of the buildings within 100 ft on either or both sides, subject to a floor of 40 ft and never more than the district requires.
Residential/Resource Conservation - A one-family dwelling is not permitted by right in RRC: it takes site plan approval, and this is the only district in the town where that is so. Underwrite RRC as forest and recreation land rather than as a housing site.
- The 400 ft of lot width applies except for hunting and fishing camps, and a 100 ft stream setback runs beside the yards.
- Agriculture, forestry and hunting or fishing camps and cabins are permitted by right; campgrounds, clubs or lodges, golf courses, group camps, mining and quarrying take site plan approval.
- Multi-family, senior housing and assisted living are all unavailable here, as are bed-and-breakfasts, restaurants, taverns, retail and offices.
- Accessory structures take a 15 ft setback, but one of 100 sq ft or larger is subject to the shoreline setbacks, and one of any size takes the same front yard as a principal building.
- The front yard may instead equal the average depth of the buildings within 100 ft on either or both sides, subject to a floor of 40 ft and never more than the district requires.
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 ResidentialA dwelling must have at least 600 sq ft of floor area in every district, so a small unit is not automatically the easy option.
- Neighborhood CommercialA dwelling must have at least 600 sq ft of floor area in every district, so a small unit is not automatically the easy option.
- Residential Moderate DensityA dwelling must have at least 600 sq ft of floor area in every district, so a small unit is not automatically the easy option.
- Residential Low DensityA dwelling must have at least 600 sq ft of floor area in every district, so a small unit is not automatically the easy option.
- Residential/Resource ConservationA dwelling must have at least 600 sq ft of floor area 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. The Town of Day has no local short-term rental law, and that is not the same as permission. Confirm the Town's position with the Code Enforcement Officer in writing before counting on short-stay income on a Sacandaga parcel. Separate question from whether you can build the unit.
- Zoning codewww.townofday.com/uploads/1/4/5/5/145564982/updatedzoning-law-merged_merged_1.pdf
- 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 $40,848 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: the Offsite / Aldo cost engine and zoning dataset.