Not the same as the Village of Caledonia. No ADU rule found in the Village of Caledonia code. See Livingston County. Check which one is on your property tax bill.
Caledonia adopted a clear ADU law in late 2025: attached, converted or new detached units up to half the house size, two bedrooms, owner on site, rentals of six months or more, with a yearly permit.
The code describes a way to approve an ADU with a permit, without a special public hearing for the ADU itself.
Whether any of this applies to your lot depends on your zoning district and your property.
The rules we found
| What the code says | Allowed with a permit |
|---|---|
| Detached (backyard) unit | Yes: in an existing accessory building or a new detached accessory building that meets the zoning rules |
| Inside or attached | Yes, inside or as an addition to the house |
| Size limit | At least 300 sq ft of living space; no more than 50% of the main house's living space |
| Bedrooms | 2 |
| Owner must live on site | Yes. The owner's primary residence is one of the units; affidavit at application and after a sale |
| How approval works | ADU permit from the Zoning Enforcement Officer; Planning Board site plan approval for the first permit; renewed yearly and within 60 days of a sale |
| Other rules | Allowed in the R-1 and R-R zoning districts, one per lot. The ADU can be no taller than 25 ft or the house, whichever is lower. Rentals must last at least six months, and the lot needs three off-street parking spaces, one of them for the ADU. If you have a well or septic system, the county health department must sign off. |
Code section: §130-85.2 Accessory dwelling units. November 13, 2025 (Local Law 2 of 2025)
What the size rule means for your house
With a 1,600 sq ft house, the largest ADU this rule allows is about 800 sq ft.
The smallest ADU allowed here is 300 sq ft, so the house needs about 600 sq ft or more for any ADU.
sq ft
Rounded down to the nearest 10 sq ft. Towns measure differently (some count only finished living space, some leave out the garage), so ask the code office how it measures yours.
What this means for your plans
- The owner has to live on the property. If you plan to move away, spend winters somewhere else or sell, read the owner rule above closely. Renting and owner rules.
Before you spend money on drawings
- Confirm the Town of Caledonia governs your lot: it should be the municipality on your property tax bill.
- Find your zoning district on the municipal zoning map; the rules above can differ by district.
- Call or write the code office with your address and what you’re picturing, and ask for the answer and the code section in writing.
- On septic or a well? Ask the Livingston County health department whether the system can serve an extra bedroom. On public sewer? Ask your sewer district.
Our guides explain the approval process, site and utility checks and what an ADU costs.
Sources
General information, not legal advice. The Town of Caledonia decides what can be built on your property.